rollmorad hinzugefügt
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/********************************************************************
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* *
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* THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
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* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
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* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
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* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
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* *
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* THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2007 *
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* by the Xiph.Org Foundation http://www.xiph.org/ *
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* *
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********************************************************************
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function:
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last mod: $Id: theora.h,v 1.8 2004/03/15 22:17:32 derf Exp $
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********************************************************************/
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/**\mainpage
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*
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* \section intro Introduction
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*
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* This is the documentation for <tt>libtheora</tt> C API.
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* The current reference
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* implementation for <a href="http://www.theora.org/">Theora</a>, a free,
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* patent-unencumbered video codec.
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* Theora is derived from On2's VP3 codec with additional features and
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* integration for Ogg multimedia formats by
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* <a href="http://www.xiph.org/">the Xiph.Org Foundation</a>.
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* Complete documentation of the format itself is available in
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* <a href="http://www.theora.org/doc/Theora_I_spec.pdf">the Theora
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* specification</a>.
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*
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* \subsection Organization
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*
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* The functions documented here are actually subdivided into three
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* separate libraries:
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* - <tt>libtheoraenc</tt> contains the encoder interface,
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* described in \ref encfuncs.
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* - <tt>libtheoradec</tt> contains the decoder interface and
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* routines shared with the encoder.
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* You must also link to this if you link to <tt>libtheoraenc</tt>.
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* The routines in this library are described in \ref decfuncs and
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* \ref basefuncs.
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* - <tt>libtheora</tt> contains the \ref oldfuncs.
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*
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* New code should link to <tt>libtheoradec</tt> and, if using encoder
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* features, <tt>libtheoraenc</tt>. Together these two export both
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* the standard and the legacy API, so this is all that is needed by
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* any code. The older <tt>libtheora</tt> library is provided just for
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* compatibility with older build configurations.
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*
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* In general the recommended 1.x API symbols can be distinguished
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* by their <tt>th_</tt> or <tt>TH_</tt> namespace prefix.
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* The older, legacy API uses <tt>theora_</tt> or <tt>OC_</tt>
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* prefixes instead.
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*/
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/**\file
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* The shared <tt>libtheoradec</tt> and <tt>libtheoraenc</tt> C API.
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* You don't need to include this directly.*/
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#if !defined(_O_THEORA_CODEC_H_)
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# define _O_THEORA_CODEC_H_ (1)
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# include <ogg/ogg.h>
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#if defined(__cplusplus)
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extern "C" {
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#endif
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/**\name Return codes*/
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/*@{*/
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/**An invalid pointer was provided.*/
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#define TH_EFAULT (-1)
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/**An invalid argument was provided.*/
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#define TH_EINVAL (-10)
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/**The contents of the header were incomplete, invalid, or unexpected.*/
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#define TH_EBADHEADER (-20)
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/**The header does not belong to a Theora stream.*/
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#define TH_ENOTFORMAT (-21)
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/**The bitstream version is too high.*/
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#define TH_EVERSION (-22)
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/**The specified function is not implemented.*/
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#define TH_EIMPL (-23)
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/**There were errors in the video data packet.*/
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#define TH_EBADPACKET (-24)
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/**The decoded packet represented a dropped frame.
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The player can continue to display the current frame, as the contents of the
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decoded frame buffer have not changed.*/
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#define TH_DUPFRAME (1)
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/*@}*/
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/**The currently defined color space tags.
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* See <a href="http://www.theora.org/doc/Theora_I_spec.pdf">the Theora
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* specification</a>, Chapter 4, for exact details on the meaning of each of
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* these color spaces.*/
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typedef enum{
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/**The color space was not specified at the encoder.
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It may be conveyed by an external means.*/
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TH_CS_UNSPECIFIED,
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/**A color space designed for NTSC content.*/
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TH_CS_ITU_REC_470M,
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/**A color space designed for PAL/SECAM content.*/
|
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TH_CS_ITU_REC_470BG,
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/**The total number of currently defined color spaces.*/
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TH_CS_NSPACES
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}th_colorspace;
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|
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/**The currently defined pixel format tags.
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||||
* See <a href="http://www.theora.org/doc/Theora_I_spec.pdf">the Theora
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* specification</a>, Section 4.4, for details on the precise sample
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* locations.*/
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typedef enum{
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/**Chroma decimation by 2 in both the X and Y directions (4:2:0).*/
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TH_PF_420,
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/**Currently reserved.*/
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TH_PF_RSVD,
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/**Chroma decimation by 2 in the X direction (4:2:2).*/
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TH_PF_422,
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/**No chroma decimation (4:4:4).*/
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TH_PF_444,
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||||
/**The total number of currently defined pixel formats.*/
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TH_PF_NFORMATS
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}th_pixel_fmt;
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||||
|
||||
|
||||
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/**A buffer for a single color plane in an uncompressed image.
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* This contains the image data in a left-to-right, top-down format.
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* Each row of pixels is stored contiguously in memory, but successive rows
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* need not be.
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* Use \a stride to compute the offset of the next row.
|
||||
* The encoder accepts both positive \a stride values (top-down in memory) and
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* negative (bottom-up in memory).
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||||
* The decoder currently always generates images with positive strides.*/
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typedef struct{
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/**The width of this plane.*/
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int width;
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/**The height of this plane.*/
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int height;
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/**The offset in bytes between successive rows.*/
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int stride;
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/**A pointer to the beginning of the first row.*/
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unsigned char *data;
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}th_img_plane;
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|
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/**A complete image buffer for an uncompressed frame.
|
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* The chroma planes may be decimated by a factor of two in either direction,
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* as indicated by th_info#pixel_fmt.
|
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* The width and height of the Y' plane must be multiples of 16.
|
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* They may need to be cropped for display, using the rectangle specified by
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* th_info#pic_x, th_info#pic_y, th_info#pic_width, and
|
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* th_info#pic_height.
|
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* All samples are 8 bits.
|
||||
* \note The term YUV often used to describe a colorspace is ambiguous.
|
||||
* The exact parameters of the RGB to YUV conversion process aside, in many
|
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* contexts the U and V channels actually have opposite meanings.
|
||||
* To avoid this confusion, we are explicit: the name of the color channels are
|
||||
* Y'CbCr, and they appear in that order, always.
|
||||
* The prime symbol denotes that the Y channel is non-linear.
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||||
* Cb and Cr stand for "Chroma blue" and "Chroma red", respectively.*/
|
||||
typedef th_img_plane th_ycbcr_buffer[3];
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||||
|
||||
/**Theora bitstream information.
|
||||
* This contains the basic playback parameters for a stream, and corresponds to
|
||||
* the initial 'info' header packet.
|
||||
* To initialize an encoder, the application fills in this structure and
|
||||
* passes it to th_encode_alloc().
|
||||
* A default encoding mode is chosen based on the values of the #quality and
|
||||
* #target_bitrate fields.
|
||||
* On decode, it is filled in by th_decode_headerin(), and then passed to
|
||||
* th_decode_alloc().
|
||||
*
|
||||
* Encoded Theora frames must be a multiple of 16 in size;
|
||||
* this is what the #frame_width and #frame_height members represent.
|
||||
* To handle arbitrary picture sizes, a crop rectangle is specified in the
|
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* #pic_x, #pic_y, #pic_width and #pic_height members.
|
||||
*
|
||||
* All frame buffers contain pointers to the full, padded frame.
|
||||
* However, the current encoder <em>will not</em> reference pixels outside of
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||||
* the cropped picture region, and the application does not need to fill them
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||||
* in.
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||||
* The decoder <em>will</em> allocate storage for a full frame, but the
|
||||
* application <em>should not</em> rely on the padding containing sensible
|
||||
* data.
|
||||
*
|
||||
* It is also generally recommended that the offsets and sizes should still be
|
||||
* multiples of 2 to avoid chroma sampling shifts when chroma is sub-sampled.
|
||||
* See <a href="http://www.theora.org/doc/Theora_I_spec.pdf">the Theora
|
||||
* specification</a>, Section 4.4, for more details.
|
||||
*
|
||||
* Frame rate, in frames per second, is stored as a rational fraction, as is
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||||
* the pixel aspect ratio.
|
||||
* Note that this refers to the aspect ratio of the individual pixels, not of
|
||||
* the overall frame itself.
|
||||
* The frame aspect ratio can be computed from pixel aspect ratio using the
|
||||
* image dimensions.*/
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||||
typedef struct{
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||||
/**\name Theora version
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||||
* Bitstream version information.*/
|
||||
/*@{*/
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||||
unsigned char version_major;
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||||
unsigned char version_minor;
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||||
unsigned char version_subminor;
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||||
/*@}*/
|
||||
/**The encoded frame width.
|
||||
* This must be a multiple of 16, and less than 1048576.*/
|
||||
ogg_uint32_t frame_width;
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||||
/**The encoded frame height.
|
||||
* This must be a multiple of 16, and less than 1048576.*/
|
||||
ogg_uint32_t frame_height;
|
||||
/**The displayed picture width.
|
||||
* This must be no larger than width.*/
|
||||
ogg_uint32_t pic_width;
|
||||
/**The displayed picture height.
|
||||
* This must be no larger than height.*/
|
||||
ogg_uint32_t pic_height;
|
||||
/**The X offset of the displayed picture.
|
||||
* This must be no larger than #frame_width-#pic_width or 255, whichever is
|
||||
* smaller.*/
|
||||
ogg_uint32_t pic_x;
|
||||
/**The Y offset of the displayed picture.
|
||||
* This must be no larger than #frame_height-#pic_height, and
|
||||
* #frame_height-#pic_height-#pic_y must be no larger than 255.
|
||||
* This slightly funny restriction is due to the fact that the offset is
|
||||
* specified from the top of the image for consistency with the standard
|
||||
* graphics left-handed coordinate system used throughout this API, while it
|
||||
* is stored in the encoded stream as an offset from the bottom.*/
|
||||
ogg_uint32_t pic_y;
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||||
/**\name Frame rate
|
||||
* The frame rate, as a fraction.
|
||||
* If either is 0, the frame rate is undefined.*/
|
||||
/*@{*/
|
||||
ogg_uint32_t fps_numerator;
|
||||
ogg_uint32_t fps_denominator;
|
||||
/*@}*/
|
||||
/**\name Aspect ratio
|
||||
* The aspect ratio of the pixels.
|
||||
* If either value is zero, the aspect ratio is undefined.
|
||||
* If not specified by any external means, 1:1 should be assumed.
|
||||
* The aspect ratio of the full picture can be computed as
|
||||
* \code
|
||||
* aspect_numerator*pic_width/(aspect_denominator*pic_height).
|
||||
* \endcode */
|
||||
/*@{*/
|
||||
ogg_uint32_t aspect_numerator;
|
||||
ogg_uint32_t aspect_denominator;
|
||||
/*@}*/
|
||||
/**The color space.*/
|
||||
th_colorspace colorspace;
|
||||
/**The pixel format.*/
|
||||
th_pixel_fmt pixel_fmt;
|
||||
/**The target bit-rate in bits per second.
|
||||
If initializing an encoder with this struct, set this field to a non-zero
|
||||
value to activate CBR encoding by default.*/
|
||||
/*TODO: Current encoder does not support CBR mode, or anything like it.
|
||||
We also don't really know what nominal rate each quality level
|
||||
corresponds to yet.*/
|
||||
int target_bitrate;
|
||||
/**The target quality level.
|
||||
Valid values range from 0 to 63, inclusive, with higher values giving
|
||||
higher quality.
|
||||
If initializing an encoder with this struct, and #target_bitrate is set
|
||||
to zero, VBR encoding at this quality will be activated by default.*/
|
||||
/*Currently this is set so that a qi of 0 corresponds to distortions of 24
|
||||
times the JND, and each increase by 16 halves that value.
|
||||
This gives us fine discrimination at low qualities, yet effective rate
|
||||
control at high qualities.
|
||||
The qi value 63 is special, however.
|
||||
For this, the highest quality, we use one half of a JND for our threshold.
|
||||
Due to the lower bounds placed on allowable quantizers in Theora, we will
|
||||
not actually be able to achieve quality this good, but this should
|
||||
provide as close to visually lossless quality as Theora is capable of.
|
||||
We could lift the quantizer restrictions without breaking VP3.1
|
||||
compatibility, but this would result in quantized coefficients that are
|
||||
too large for the current bitstream to be able to store.
|
||||
We'd have to redesign the token syntax to store these large coefficients,
|
||||
which would make transcoding complex.*/
|
||||
int quality;
|
||||
/**The amount to shift to extract the last keyframe number from the granule
|
||||
* position.
|
||||
* This can be at most 31.
|
||||
* th_info_init() will set this to a default value (currently <tt>6</tt>,
|
||||
* which is good for streaming applications), but you can set it to 0 to
|
||||
* make every frame a keyframe.
|
||||
* The maximum distance between key frames is
|
||||
* <tt>1<<#keyframe_granule_shift</tt>.
|
||||
* The keyframe frequency can be more finely controlled with
|
||||
* #TH_ENCCTL_SET_KEYFRAME_FREQUENCY_FORCE, which can also be adjusted
|
||||
* during encoding (for example, to force the next frame to be a keyframe),
|
||||
* but it cannot be set larger than the amount permitted by this field after
|
||||
* the headers have been output.*/
|
||||
int keyframe_granule_shift;
|
||||
}th_info;
|
||||
|
||||
/**The comment information.
|
||||
*
|
||||
* This structure holds the in-stream metadata corresponding to
|
||||
* the 'comment' header packet.
|
||||
* The comment header is meant to be used much like someone jotting a quick
|
||||
* note on the label of a video.
|
||||
* It should be a short, to the point text note that can be more than a couple
|
||||
* words, but not more than a short paragraph.
|
||||
*
|
||||
* The metadata is stored as a series of (tag, value) pairs, in
|
||||
* length-encoded string vectors.
|
||||
* The first occurrence of the '=' character delimits the tag and value.
|
||||
* A particular tag may occur more than once, and order is significant.
|
||||
* The character set encoding for the strings is always UTF-8, but the tag
|
||||
* names are limited to ASCII, and treated as case-insensitive.
|
||||
* See <a href="http://www.theora.org/doc/Theora_I_spec.pdf">the Theora
|
||||
* specification</a>, Section 6.3.3 for details.
|
||||
*
|
||||
* In filling in this structure, th_decode_headerin() will null-terminate
|
||||
* the user_comment strings for safety.
|
||||
* However, the bitstream format itself treats them as 8-bit clean vectors,
|
||||
* possibly containing null characters, and so the length array should be
|
||||
* treated as their authoritative length.
|
||||
*/
|
||||
typedef struct th_comment{
|
||||
/**The array of comment string vectors.*/
|
||||
char **user_comments;
|
||||
/**An array of the corresponding length of each vector, in bytes.*/
|
||||
int *comment_lengths;
|
||||
/**The total number of comment strings.*/
|
||||
int comments;
|
||||
/**The null-terminated vendor string.
|
||||
This identifies the software used to encode the stream.*/
|
||||
char *vendor;
|
||||
}th_comment;
|
||||
|
||||
|
||||
|
||||
/**A single base matrix.*/
|
||||
typedef unsigned char th_quant_base[64];
|
||||
|
||||
/**A set of \a qi ranges.*/
|
||||
typedef struct{
|
||||
/**The number of ranges in the set.*/
|
||||
int nranges;
|
||||
/**The size of each of the #nranges ranges.
|
||||
These must sum to 63.*/
|
||||
const int *sizes;
|
||||
/**#nranges <tt>+1</tt> base matrices.
|
||||
Matrices \a i and <tt>i+1</tt> form the endpoints of range \a i.*/
|
||||
const th_quant_base *base_matrices;
|
||||
}th_quant_ranges;
|
||||
|
||||
/**A complete set of quantization parameters.
|
||||
The quantizer for each coefficient is calculated as:
|
||||
\code
|
||||
Q=MAX(MIN(qmin[qti][ci!=0],scale[ci!=0][qi]*base[qti][pli][qi][ci]/100),
|
||||
1024).
|
||||
\endcode
|
||||
|
||||
\a qti is the quantization type index: 0 for intra, 1 for inter.
|
||||
<tt>ci!=0</tt> is 0 for the DC coefficient and 1 for AC coefficients.
|
||||
\a qi is the quality index, ranging between 0 (low quality) and 63 (high
|
||||
quality).
|
||||
\a pli is the color plane index: 0 for Y', 1 for Cb, 2 for Cr.
|
||||
\a ci is the DCT coefficient index.
|
||||
Coefficient indices correspond to the normal 2D DCT block
|
||||
ordering--row-major with low frequencies first--\em not zig-zag order.
|
||||
|
||||
Minimum quantizers are constant, and are given by:
|
||||
\code
|
||||
qmin[2][2]={{4,2},{8,4}}.
|
||||
\endcode
|
||||
|
||||
Parameters that can be stored in the bitstream are as follows:
|
||||
- The two scale matrices ac_scale and dc_scale.
|
||||
\code
|
||||
scale[2][64]={dc_scale,ac_scale}.
|
||||
\endcode
|
||||
- The base matrices for each \a qi, \a qti and \a pli (up to 384 in all).
|
||||
In order to avoid storing a full 384 base matrices, only a sparse set of
|
||||
matrices are stored, and the rest are linearly interpolated.
|
||||
This is done as follows.
|
||||
For each \a qti and \a pli, a series of \a n \a qi ranges is defined.
|
||||
The size of each \a qi range can vary arbitrarily, but they must sum to
|
||||
63.
|
||||
Then, <tt>n+1</tt> matrices are specified, one for each endpoint of the
|
||||
ranges.
|
||||
For interpolation purposes, each range's endpoints are the first \a qi
|
||||
value it contains and one past the last \a qi value it contains.
|
||||
Fractional values are rounded to the nearest integer, with ties rounded
|
||||
away from zero.
|
||||
|
||||
Base matrices are stored by reference, so if the same matrices are used
|
||||
multiple times, they will only appear once in the bitstream.
|
||||
The bitstream is also capable of omitting an entire set of ranges and
|
||||
its associated matrices if they are the same as either the previous
|
||||
set (indexed in row-major order) or if the inter set is the same as the
|
||||
intra set.
|
||||
|
||||
- Loop filter limit values.
|
||||
The same limits are used for the loop filter in all color planes, despite
|
||||
potentially differing levels of quantization in each.
|
||||
|
||||
For the current encoder, <tt>scale[ci!=0][qi]</tt> must be no greater
|
||||
than <tt>scale[ci!=0][qi-1]</tt> and <tt>base[qti][pli][qi][ci]</tt> must
|
||||
be no greater than <tt>base[qti][pli][qi-1][ci]</tt>.
|
||||
These two conditions ensure that the actual quantizer for a given \a qti,
|
||||
\a pli, and \a ci does not increase as \a qi increases.
|
||||
This is not required by the decoder.*/
|
||||
typedef struct{
|
||||
/**The DC scaling factors.*/
|
||||
ogg_uint16_t dc_scale[64];
|
||||
/**The AC scaling factors.*/
|
||||
ogg_uint16_t ac_scale[64];
|
||||
/**The loop filter limit values.*/
|
||||
unsigned char loop_filter_limits[64];
|
||||
/**The \a qi ranges for each \a ci and \a pli.*/
|
||||
th_quant_ranges qi_ranges[2][3];
|
||||
}th_quant_info;
|
||||
|
||||
|
||||
|
||||
/**The number of Huffman tables used by Theora.*/
|
||||
#define TH_NHUFFMAN_TABLES (80)
|
||||
/**The number of DCT token values in each table.*/
|
||||
#define TH_NDCT_TOKENS (32)
|
||||
|
||||
/**A Huffman code for a Theora DCT token.
|
||||
* Each set of Huffman codes in a given table must form a complete, prefix-free
|
||||
* code.
|
||||
* There is no requirement that all the tokens in a table have a valid code,
|
||||
* but the current encoder is not optimized to take advantage of this.
|
||||
* If each of the five grouops of 16 tables does not contain at least one table
|
||||
* with a code for every token, then the encoder may fail to encode certain
|
||||
* frames.
|
||||
* The complete table in the first group of 16 does not have to be in the same
|
||||
* place as the complete table in the other groups, but the complete tables in
|
||||
* the remaining four groups must all be in the same place.*/
|
||||
typedef struct{
|
||||
/**The bit pattern for the code, with the LSbit of the pattern aligned in
|
||||
* the LSbit of the word.*/
|
||||
ogg_uint32_t pattern;
|
||||
/**The number of bits in the code.
|
||||
* This must be between 0 and 32, inclusive.*/
|
||||
int nbits;
|
||||
}th_huff_code;
|
||||
|
||||
|
||||
|
||||
/**\defgroup basefuncs Functions Shared by Encode and Decode*/
|
||||
/*@{*/
|
||||
/**\name Basic shared functions*/
|
||||
/*@{*/
|
||||
/**Retrieves a human-readable string to identify the library vendor and
|
||||
* version.
|
||||
* \return the version string.*/
|
||||
extern const char *th_version_string(void);
|
||||
/**Retrieves the library version number.
|
||||
* This is the highest bitstream version that the encoder library will produce,
|
||||
* or that the decoder library can decode.
|
||||
* This number is composed of a 16-bit major version, 8-bit minor version
|
||||
* and 8 bit sub-version, composed as follows:
|
||||
* \code
|
||||
* (VERSION_MAJOR<<16)+(VERSION_MINOR<<8)+(VERSION_SUBMINOR)
|
||||
* \endcode
|
||||
* \return the version number.*/
|
||||
extern ogg_uint32_t th_version_number(void);
|
||||
/**Converts a granule position to an absolute frame index, starting at
|
||||
* <tt>0</tt>.
|
||||
* The granule position is interpreted in the context of a given
|
||||
* #th_enc_ctx or #th_dec_ctx handle (either will suffice).
|
||||
* \param _encdec A previously allocated #th_enc_ctx or #th_dec_ctx
|
||||
* handle.
|
||||
* \param _granpos The granule position to convert.
|
||||
* \returns The absolute frame index corresponding to \a _granpos.
|
||||
* \retval -1 The given granule position was invalid (i.e. negative).*/
|
||||
extern ogg_int64_t th_granule_frame(void *_encdec,ogg_int64_t _granpos);
|
||||
/**Converts a granule position to an absolute time in seconds.
|
||||
* The granule position is interpreted in the context of a given
|
||||
* #th_enc_ctx or #th_dec_ctx handle (either will suffice).
|
||||
* \param _encdec A previously allocated #th_enc_ctx or #th_dec_ctx
|
||||
* handle.
|
||||
* \param _granpos The granule position to convert.
|
||||
* \return The absolute time in seconds corresponding to \a _granpos.
|
||||
* This is the "end time" for the frame, or the latest time it should
|
||||
* be displayed.
|
||||
* It is not the presentation time.
|
||||
* \retval -1 The given granule position was invalid (i.e. negative).*/
|
||||
extern double th_granule_time(void *_encdec,ogg_int64_t _granpos);
|
||||
/**Determines whether a Theora packet is a header or not.
|
||||
* This function does no verification beyond checking the packet type bit, so
|
||||
* it should not be used for bitstream identification; use
|
||||
* th_decode_headerin() for that.
|
||||
* As per the Theora specification, an empty (0-byte) packet is treated as a
|
||||
* data packet (a delta frame with no coded blocks).
|
||||
* \param _op An <tt>ogg_packet</tt> containing encoded Theora data.
|
||||
* \retval 1 The packet is a header packet
|
||||
* \retval 0 The packet is a video data packet.*/
|
||||
extern int th_packet_isheader(ogg_packet *_op);
|
||||
/**Determines whether a theora packet is a key frame or not.
|
||||
* This function does no verification beyond checking the packet type and
|
||||
* key frame bits, so it should not be used for bitstream identification; use
|
||||
* th_decode_headerin() for that.
|
||||
* As per the Theora specification, an empty (0-byte) packet is treated as a
|
||||
* delta frame (with no coded blocks).
|
||||
* \param _op An <tt>ogg_packet</tt> containing encoded Theora data.
|
||||
* \retval 1 The packet contains a key frame.
|
||||
* \retval 0 The packet contains a delta frame.
|
||||
* \retval -1 The packet is not a video data packet.*/
|
||||
extern int th_packet_iskeyframe(ogg_packet *_op);
|
||||
/*@}*/
|
||||
|
||||
|
||||
/**\name Functions for manipulating header data*/
|
||||
/*@{*/
|
||||
/**Initializes a th_info structure.
|
||||
* This should be called on a freshly allocated #th_info structure before
|
||||
* attempting to use it.
|
||||
* \param _info The #th_info struct to initialize.*/
|
||||
extern void th_info_init(th_info *_info);
|
||||
/**Clears a #th_info structure.
|
||||
* This should be called on a #th_info structure after it is no longer
|
||||
* needed.
|
||||
* \param _info The #th_info struct to clear.*/
|
||||
extern void th_info_clear(th_info *_info);
|
||||
|
||||
/**Initialize a #th_comment structure.
|
||||
* This should be called on a freshly allocated #th_comment structure
|
||||
* before attempting to use it.
|
||||
* \param _tc The #th_comment struct to initialize.*/
|
||||
extern void th_comment_init(th_comment *_tc);
|
||||
/**Add a comment to an initialized #th_comment structure.
|
||||
* \note Neither th_comment_add() nor th_comment_add_tag() support
|
||||
* comments containing null values, although the bitstream format does
|
||||
* support them.
|
||||
* To add such comments you will need to manipulate the #th_comment
|
||||
* structure directly.
|
||||
* \param _tc The #th_comment struct to add the comment to.
|
||||
* \param _comment Must be a null-terminated UTF-8 string containing the
|
||||
* comment in "TAG=the value" form.*/
|
||||
extern void th_comment_add(th_comment *_tc, char *_comment);
|
||||
/**Add a comment to an initialized #th_comment structure.
|
||||
* \note Neither th_comment_add() nor th_comment_add_tag() support
|
||||
* comments containing null values, although the bitstream format does
|
||||
* support them.
|
||||
* To add such comments you will need to manipulate the #th_comment
|
||||
* structure directly.
|
||||
* \param _tc The #th_comment struct to add the comment to.
|
||||
* \param _tag A null-terminated string containing the tag associated with
|
||||
* the comment.
|
||||
* \param _val The corresponding value as a null-terminated string.*/
|
||||
extern void th_comment_add_tag(th_comment *_tc,char *_tag,char *_val);
|
||||
/**Look up a comment value by its tag.
|
||||
* \param _tc An initialized #th_comment structure.
|
||||
* \param _tag The tag to look up.
|
||||
* \param _count The instance of the tag.
|
||||
* The same tag can appear multiple times, each with a distinct
|
||||
* value, so an index is required to retrieve them all.
|
||||
* The order in which these values appear is significant and
|
||||
* should be preserved.
|
||||
* Use th_comment_query_count() to get the legal range for
|
||||
* the \a _count parameter.
|
||||
* \return A pointer to the queried tag's value.
|
||||
* This points directly to data in the #th_comment structure.
|
||||
* It should not be modified or freed by the application, and
|
||||
* modifications to the structure may invalidate the pointer.
|
||||
* \retval NULL If no matching tag is found.*/
|
||||
extern char *th_comment_query(th_comment *_tc,char *_tag,int _count);
|
||||
/**Look up the number of instances of a tag.
|
||||
* Call this first when querying for a specific tag and then iterate over the
|
||||
* number of instances with separate calls to th_comment_query() to
|
||||
* retrieve all the values for that tag in order.
|
||||
* \param _tc An initialized #th_comment structure.
|
||||
* \param _tag The tag to look up.
|
||||
* \return The number on instances of this particular tag.*/
|
||||
extern int th_comment_query_count(th_comment *_tc,char *_tag);
|
||||
/**Clears a #th_comment structure.
|
||||
* This should be called on a #th_comment structure after it is no longer
|
||||
* needed.
|
||||
* It will free all memory used by the structure members.
|
||||
* \param _tc The #th_comment struct to clear.*/
|
||||
extern void th_comment_clear(th_comment *_tc);
|
||||
/*@}*/
|
||||
/*@}*/
|
||||
|
||||
|
||||
|
||||
#if defined(__cplusplus)
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif
|
||||
@@ -0,0 +1,290 @@
|
||||
/********************************************************************
|
||||
* *
|
||||
* THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
|
||||
* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
|
||||
* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
|
||||
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
|
||||
* *
|
||||
* THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2007 *
|
||||
* by the Xiph.Org Foundation http://www.xiph.org/ *
|
||||
* *
|
||||
********************************************************************
|
||||
|
||||
function:
|
||||
last mod: $Id: theora.h,v 1.8 2004/03/15 22:17:32 derf Exp $
|
||||
|
||||
********************************************************************/
|
||||
|
||||
/**\file
|
||||
* The <tt>libtheoradec</tt> C decoding API.*/
|
||||
|
||||
#if !defined(_O_THEORA_THEORADEC_H_)
|
||||
# define _O_THEORA_THEORADEC_H_ (1)
|
||||
# include <ogg/ogg.h>
|
||||
# include "codec.h"
|
||||
|
||||
#if defined(__cplusplus)
|
||||
extern "C" {
|
||||
#endif
|
||||
|
||||
|
||||
|
||||
/**\name th_decode_ctl() codes
|
||||
* \anchor decctlcodes
|
||||
* These are the available request codes for th_decode_ctl().
|
||||
* By convention, these are odd, to distinguish them from the
|
||||
* \ref encctlcodes "encoder control codes".
|
||||
* Keep any experimental or vendor-specific values above \c 0x8000.*/
|
||||
/*@{*/
|
||||
/**Gets the maximum post-processing level.
|
||||
*
|
||||
* \param[out] _buf int: The maximum post-processing level.
|
||||
* \retval TH_EFAULT \a _dec_ctx or \a _buf is <tt>NULL</tt>.
|
||||
* \retval TH_EINVAL \a _buf_sz is not <tt>sizeof(int)</tt>.
|
||||
* \retval TH_EIMPL Not supported by this implementation.*/
|
||||
#define TH_DECCTL_GET_PPLEVEL_MAX (1)
|
||||
/**Sets the post-processing level.
|
||||
* By default, post-processing is disabled.
|
||||
*
|
||||
* \param[in] _buf int: The new post-processing level.
|
||||
* 0 to disable; larger values use more CPU.
|
||||
* \retval TH_EFAULT \a _dec_ctx or \a _buf is <tt>NULL</tt>.
|
||||
* \retval TH_EINVAL \a _buf_sz is not <tt>sizeof(int)</tt>, or the
|
||||
* post-processing level is out of bounds.
|
||||
* The maximum post-processing level may be
|
||||
* implementation-specific, and can be obtained via
|
||||
* #TH_DECCTL_GET_PPLEVEL_MAX.
|
||||
* \retval TH_EIMPL Not supported by this implementation.*/
|
||||
#define TH_DECCTL_SET_PPLEVEL (3)
|
||||
/**Sets the granule position.
|
||||
* Call this after a seek, before decoding the first frame, to ensure that the
|
||||
* proper granule position is returned for all subsequent frames.
|
||||
* If you track timestamps yourself and do not use the granule position
|
||||
* returned by the decoder, then you need not call this function.
|
||||
*
|
||||
* \param[in] _buf <tt>ogg_int64_t</tt>: The granule position of the next
|
||||
* frame.
|
||||
* \retval TH_EFAULT \a _dec_ctx or \a _buf is <tt>NULL</tt>.
|
||||
* \retval TH_EINVAL \a _buf_sz is not <tt>sizeof(ogg_int64_t)</tt>, or the
|
||||
* granule position is negative.*/
|
||||
#define TH_DECCTL_SET_GRANPOS (5)
|
||||
/**Sets the striped decode callback function.
|
||||
* If set, this function will be called as each piece of a frame is fully
|
||||
* decoded in th_decode_packetin().
|
||||
* You can pass in a #th_stripe_callback with
|
||||
* th_stripe_callback#stripe_decoded set to <tt>NULL</tt> to disable the
|
||||
* callbacks at any point.
|
||||
* Enabling striped decode does not prevent you from calling
|
||||
* th_decode_ycbcr_out() after the frame is fully decoded.
|
||||
*
|
||||
* \param[in] _buf #th_stripe_callback: The callback parameters.
|
||||
* \retval TH_EFAULT \a _dec_ctx or \a _buf is <tt>NULL</tt>.
|
||||
* \retval TH_EINVAL \a _buf_sz is not
|
||||
* <tt>sizeof(th_stripe_callback)</tt>.*/
|
||||
#define TH_DECCTL_SET_STRIPE_CB (7)
|
||||
/*@}*/
|
||||
|
||||
|
||||
|
||||
/**A callback function for striped decode.
|
||||
* This is a function pointer to an application-provided function that will be
|
||||
* called each time a section of the image is fully decoded in
|
||||
* th_decode_packetin().
|
||||
* This allows the application to process the section immediately, while it is
|
||||
* still in cache.
|
||||
* Note that the frame is decoded bottom to top, so \a _yfrag0 will steadily
|
||||
* decrease with each call until it reaches 0, at which point the full frame
|
||||
* is decoded.
|
||||
* The number of fragment rows made available in each call depends on the pixel
|
||||
* format and the number of post-processing filters enabled, and may not even
|
||||
* be constant for the entire frame.
|
||||
* If a non-<tt>NULL</tt> \a _granpos pointer is passed to
|
||||
* th_decode_packetin(), the granule position for the frame will be stored
|
||||
* in it before the first callback is made.
|
||||
* If an entire frame is dropped (a 0-byte packet), then no callbacks will be
|
||||
* made at all for that frame.
|
||||
* \param _ctx An application-provided context pointer.
|
||||
* \param _buf The image buffer for the decoded frame.
|
||||
* \param _yfrag0 The Y coordinate of the first row of 8x8 fragments
|
||||
* decoded.
|
||||
* Multiply this by 8 to obtain the pixel row number in the
|
||||
* luma plane.
|
||||
* If the chroma planes are subsampled in the Y direction,
|
||||
* this will always be divisible by two.
|
||||
* \param _yfrag_end The Y coordinate of the first row of 8x8 fragments past
|
||||
* the newly decoded section.
|
||||
* If the chroma planes are subsampled in the Y direction,
|
||||
* this will always be divisible by two.
|
||||
* I.e., this section contains fragment rows
|
||||
* <tt>\a _yfrag0 ...\a _yfrag_end -1</tt>.*/
|
||||
typedef void (*th_stripe_decoded_func)(void *_ctx,th_ycbcr_buffer _buf,
|
||||
int _yfrag0,int _yfrag_end);
|
||||
|
||||
/**The striped decode callback data to pass to #TH_DECCTL_SET_STRIPE_CB.*/
|
||||
typedef struct{
|
||||
/**An application-provided context pointer.
|
||||
* This will be passed back verbatim to the application.*/
|
||||
void *ctx;
|
||||
/**The callback function pointer.*/
|
||||
th_stripe_decoded_func stripe_decoded;
|
||||
}th_stripe_callback;
|
||||
|
||||
|
||||
|
||||
/**\name Decoder state
|
||||
The following data structures are opaque, and their contents are not
|
||||
publicly defined by this API.
|
||||
Referring to their internals directly is unsupported, and may break without
|
||||
warning.*/
|
||||
/*@{*/
|
||||
/**The decoder context.*/
|
||||
typedef struct th_dec_ctx th_dec_ctx;
|
||||
/**Setup information.
|
||||
This contains auxiliary information (Huffman tables and quantization
|
||||
parameters) decoded from the setup header by th_decode_headerin() to be
|
||||
passed to th_decode_alloc().
|
||||
It can be re-used to initialize any number of decoders, and can be freed
|
||||
via th_setup_free() at any time.*/
|
||||
typedef struct th_setup_info th_setup_info;
|
||||
/*@}*/
|
||||
|
||||
|
||||
|
||||
/**\defgroup decfuncs Functions for Decoding*/
|
||||
/*@{*/
|
||||
/**\name Functions for decoding
|
||||
* You must link to <tt>libtheoradec</tt> if you use any of the
|
||||
* functions in this section.
|
||||
*
|
||||
* The functions are listed in the order they are used in a typical decode.
|
||||
* The basic steps are:
|
||||
* - Parse the header packets by repeatedly calling th_decode_headerin().
|
||||
* - Allocate a #th_dec_ctx handle with th_decode_alloc().
|
||||
* - Call th_setup_free() to free any memory used for codec setup
|
||||
* information.
|
||||
* - Perform any additional decoder configuration with th_decode_ctl().
|
||||
* - For each video data packet:
|
||||
* - Submit the packet to the decoder via th_decode_packetin().
|
||||
* - Retrieve the uncompressed video data via th_decode_ycbcr_out().
|
||||
* - Call th_decode_free() to release all decoder memory.*/
|
||||
/*@{*/
|
||||
/**Decodes the header packets of a Theora stream.
|
||||
* This should be called on the initial packets of the stream, in succession,
|
||||
* until it returns <tt>0</tt>, indicating that all headers have been
|
||||
* processed, or an error is encountered.
|
||||
* At least three header packets are required, and additional optional header
|
||||
* packets may follow.
|
||||
* This can be used on the first packet of any logical stream to determine if
|
||||
* that stream is a Theora stream.
|
||||
* \param _info A #th_info structure to fill in.
|
||||
* This must have been previously initialized with
|
||||
* th_info_init().
|
||||
* The application may immediately begin using the contents of
|
||||
* this structure after the first header is decoded, though it
|
||||
* must continue to be passed in on all subsequent calls.
|
||||
* \param _tc A #th_comment structure to fill in.
|
||||
* The application may immediately begin using the contents of
|
||||
* this structure after the second header is decoded, though it
|
||||
* must continue to be passed in on all subsequent calls.
|
||||
* \param _setup Returns a pointer to additional, private setup information
|
||||
* needed by the decoder.
|
||||
* The contents of this pointer must be initialized to
|
||||
* <tt>NULL</tt> on the first call, and the returned value must
|
||||
* continue to be passed in on all subsequent calls.
|
||||
* \param _op An <tt>ogg_packet</tt> structure which contains one of the
|
||||
* initial packets of an Ogg logical stream.
|
||||
* \return A positive value indicates that a Theora header was successfully
|
||||
* processed.
|
||||
* \retval 0 The first video data packet was encountered after all
|
||||
* required header packets were parsed.
|
||||
* The packet just passed in on this call should be saved
|
||||
* and fed to th_decode_packetin() to begin decoding
|
||||
* video data.
|
||||
* \retval TH_EFAULT One of \a _info, \a _tc, or \a _setup was
|
||||
* <tt>NULL</tt>.
|
||||
* \retval TH_EBADHEADER \a _op was <tt>NULL</tt>, the packet was not the next
|
||||
* header packet in the expected sequence, or the format
|
||||
* of the header data was invalid.
|
||||
* \retval TH_EVERSION The packet data was a Theora info header, but for a
|
||||
* bitstream version not decodable with this version of
|
||||
* <tt>libtheoradec</tt>.
|
||||
* \retval TH_ENOTFORMAT The packet was not a Theora header.
|
||||
*/
|
||||
extern int th_decode_headerin(th_info *_info,th_comment *_tc,
|
||||
th_setup_info **_setup,ogg_packet *_op);
|
||||
/**Allocates a decoder instance.
|
||||
* \param _info A #th_info struct filled via th_decode_headerin().
|
||||
* \param _setup A #th_setup_info handle returned via
|
||||
* th_decode_headerin().
|
||||
* \return The initialized #th_dec_ctx handle.
|
||||
* \retval NULL If the decoding parameters were invalid.*/
|
||||
extern th_dec_ctx *th_decode_alloc(const th_info *_info,
|
||||
const th_setup_info *_setup);
|
||||
/**Releases all storage used for the decoder setup information.
|
||||
* This should be called after you no longer want to create any decoders for
|
||||
* a stream whose headers you have parsed with th_decode_headerin().
|
||||
* \param _setup The setup information to free.
|
||||
* This can safely be <tt>NULL</tt>.*/
|
||||
extern void th_setup_free(th_setup_info *_setup);
|
||||
/**Decoder control function.
|
||||
* This is used to provide advanced control of the decoding process.
|
||||
* \param _dec A #th_dec_ctx handle.
|
||||
* \param _req The control code to process.
|
||||
* See \ref decctlcodes "the list of available control codes"
|
||||
* for details.
|
||||
* \param _buf The parameters for this control code.
|
||||
* \param _buf_sz The size of the parameter buffer.*/
|
||||
extern int th_decode_ctl(th_dec_ctx *_dec,int _req,void *_buf,
|
||||
size_t _buf_sz);
|
||||
/**Submits a packet containing encoded video data to the decoder.
|
||||
* \param _dec A #th_dec_ctx handle.
|
||||
* \param _op An <tt>ogg_packet</tt> containing encoded video data.
|
||||
* \param _granpos Returns the granule position of the decoded packet.
|
||||
* If non-<tt>NULL</tt>, the granule position for this specific
|
||||
* packet is stored in this location.
|
||||
* This is computed incrementally from previously decoded
|
||||
* packets.
|
||||
* After a seek, the correct granule position must be set via
|
||||
* #TH_DECCTL_SET_GRANPOS for this to work properly.
|
||||
* \retval 0 Success.
|
||||
* A new decoded frame can be retrieved by calling
|
||||
* th_decode_ycbcr_out().
|
||||
* \retval TH_DUPFRAME The packet represented a dropped (0-byte) frame.
|
||||
* The player can skip the call to th_decode_ycbcr_out(),
|
||||
* as the contents of the decoded frame buffer have not
|
||||
* changed.
|
||||
* \retval TH_EFAULT \a _dec or _op was <tt>NULL</tt>.
|
||||
* \retval TH_EBADPACKET \a _op does not contain encoded video data.
|
||||
* \retval TH_EIMPL The video data uses bitstream features which this
|
||||
* library does not support.*/
|
||||
extern int th_decode_packetin(th_dec_ctx *_dec,const ogg_packet *_op,
|
||||
ogg_int64_t *_granpos);
|
||||
/**Outputs the next available frame of decoded Y'CbCr data.
|
||||
* If a striped decode callback has been set with #TH_DECCTL_SET_STRIPE_CB,
|
||||
* then the application does not need to call this function.
|
||||
* \param _dec A #th_dec_ctx handle.
|
||||
* \param _ycbcr A video buffer structure to fill in.
|
||||
* <tt>libtheoradec</tt> will fill in all the members of this
|
||||
* structure, including the pointers to the uncompressed video
|
||||
* data.
|
||||
* The memory for this video data is owned by
|
||||
* <tt>libtheoradec</tt>.
|
||||
* It may be freed or overwritten without notification when
|
||||
* subsequent frames are decoded.
|
||||
* \retval 0 Success
|
||||
*/
|
||||
extern int th_decode_ycbcr_out(th_dec_ctx *_dec,
|
||||
th_ycbcr_buffer _ycbcr);
|
||||
/**Frees an allocated decoder instance.
|
||||
* \param _dec A #th_dec_ctx handle.*/
|
||||
extern void th_decode_free(th_dec_ctx *_dec);
|
||||
/*@}*/
|
||||
/*@}*/
|
||||
|
||||
|
||||
|
||||
#if defined(__cplusplus)
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif
|
||||
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Reference in New Issue
Block a user