FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
hapdec.c
Go to the documentation of this file.
1 /*
2  * Vidvox Hap decoder
3  * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
4  * Copyright (C) 2015 Tom Butterworth <bangnoise@gmail.com>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * Hap decoder
26  *
27  * Fourcc: Hap1, Hap5, HapY
28  *
29  * https://github.com/Vidvox/hap/blob/master/documentation/HapVideoDRAFT.md
30  */
31 
32 #include <stdint.h>
33 
34 #include "libavutil/imgutils.h"
35 
36 #include "avcodec.h"
37 #include "bytestream.h"
38 #include "hap.h"
39 #include "internal.h"
40 #include "snappy.h"
41 #include "texturedsp.h"
42 #include "thread.h"
43 
44 /* The first three bytes are the size of the section past the header, or zero
45  * if the length is stored in the next long word. The fourth byte in the first
46  * long word indicates the type of the current section. */
47 static int parse_section_header(GetByteContext *gbc, int *section_size,
48  enum HapSectionType *section_type)
49 {
50  if (bytestream2_get_bytes_left(gbc) < 4)
51  return AVERROR_INVALIDDATA;
52 
53  *section_size = bytestream2_get_le24(gbc);
54  *section_type = bytestream2_get_byte(gbc);
55 
56  if (*section_size == 0) {
57  if (bytestream2_get_bytes_left(gbc) < 4)
58  return AVERROR_INVALIDDATA;
59 
60  *section_size = bytestream2_get_le32(gbc);
61  }
62 
63  if (*section_size > bytestream2_get_bytes_left(gbc) || *section_size < 0)
64  return AVERROR_INVALIDDATA;
65  else
66  return 0;
67 }
68 
70 {
71  GetByteContext *gbc = &ctx->gbc;
72  int section_size;
73  enum HapSectionType section_type;
74  int is_first_table = 1, had_offsets = 0, had_compressors = 0, had_sizes = 0;
75  int i, ret;
76 
77  while (size > 0) {
78  int stream_remaining = bytestream2_get_bytes_left(gbc);
79  ret = parse_section_header(gbc, &section_size, &section_type);
80  if (ret != 0)
81  return ret;
82 
83  size -= stream_remaining - bytestream2_get_bytes_left(gbc);
84 
85  switch (section_type) {
87  ret = ff_hap_set_chunk_count(ctx, section_size, is_first_table);
88  if (ret != 0)
89  return ret;
90  for (i = 0; i < section_size; i++) {
91  ctx->chunks[i].compressor = bytestream2_get_byte(gbc) << 4;
92  }
93  had_compressors = 1;
94  is_first_table = 0;
95  break;
96  case HAP_ST_SIZE_TABLE:
97  ret = ff_hap_set_chunk_count(ctx, section_size / 4, is_first_table);
98  if (ret != 0)
99  return ret;
100  for (i = 0; i < section_size / 4; i++) {
101  ctx->chunks[i].compressed_size = bytestream2_get_le32(gbc);
102  }
103  had_sizes = 1;
104  is_first_table = 0;
105  break;
106  case HAP_ST_OFFSET_TABLE:
107  ret = ff_hap_set_chunk_count(ctx, section_size / 4, is_first_table);
108  if (ret != 0)
109  return ret;
110  for (i = 0; i < section_size / 4; i++) {
111  ctx->chunks[i].compressed_offset = bytestream2_get_le32(gbc);
112  }
113  had_offsets = 1;
114  is_first_table = 0;
115  break;
116  default:
117  break;
118  }
119  size -= section_size;
120  }
121 
122  if (!had_sizes || !had_compressors)
123  return AVERROR_INVALIDDATA;
124 
125  /* The offsets table is optional. If not present than calculate offsets by
126  * summing the sizes of preceding chunks. */
127  if (!had_offsets) {
128  size_t running_size = 0;
129  for (i = 0; i < ctx->chunk_count; i++) {
130  ctx->chunks[i].compressed_offset = running_size;
131  running_size += ctx->chunks[i].compressed_size;
132  }
133  }
134 
135  return 0;
136 }
137 
139 {
140  int i;
141  size_t running_offset = 0;
142  for (i = 0; i < ctx->chunk_count; i++) {
143  if (ctx->chunks[i].compressed_offset != running_offset
144  || ctx->chunks[i].compressor != HAP_COMP_NONE)
145  return 0;
146  running_offset += ctx->chunks[i].compressed_size;
147  }
148  return 1;
149 }
150 
152 {
153  HapContext *ctx = avctx->priv_data;
154  GetByteContext *gbc = &ctx->gbc;
155  int section_size;
156  enum HapSectionType section_type;
157  const char *compressorstr;
158  int i, ret;
159 
160  ret = parse_section_header(gbc, &section_size, &section_type);
161  if (ret != 0)
162  return ret;
163 
164  if ((avctx->codec_tag == MKTAG('H','a','p','1') && (section_type & 0x0F) != HAP_FMT_RGBDXT1) ||
165  (avctx->codec_tag == MKTAG('H','a','p','5') && (section_type & 0x0F) != HAP_FMT_RGBADXT5) ||
166  (avctx->codec_tag == MKTAG('H','a','p','Y') && (section_type & 0x0F) != HAP_FMT_YCOCGDXT5)) {
167  av_log(avctx, AV_LOG_ERROR,
168  "Invalid texture format %#04x.\n", section_type & 0x0F);
169  return AVERROR_INVALIDDATA;
170  }
171 
172  switch (section_type & 0xF0) {
173  case HAP_COMP_NONE:
174  case HAP_COMP_SNAPPY:
175  ret = ff_hap_set_chunk_count(ctx, 1, 1);
176  if (ret == 0) {
177  ctx->chunks[0].compressor = section_type & 0xF0;
178  ctx->chunks[0].compressed_offset = 0;
179  ctx->chunks[0].compressed_size = section_size;
180  }
181  if (ctx->chunks[0].compressor == HAP_COMP_NONE) {
182  compressorstr = "none";
183  } else {
184  compressorstr = "snappy";
185  }
186  break;
187  case HAP_COMP_COMPLEX:
188  ret = parse_section_header(gbc, &section_size, &section_type);
189  if (ret == 0 && section_type != HAP_ST_DECODE_INSTRUCTIONS)
190  ret = AVERROR_INVALIDDATA;
191  if (ret == 0)
192  ret = hap_parse_decode_instructions(ctx, section_size);
193  compressorstr = "complex";
194  break;
195  default:
196  ret = AVERROR_INVALIDDATA;
197  break;
198  }
199 
200  if (ret != 0)
201  return ret;
202 
203  /* Check the frame is valid and read the uncompressed chunk sizes */
204  ctx->tex_size = 0;
205  for (i = 0; i < ctx->chunk_count; i++) {
206  HapChunk *chunk = &ctx->chunks[i];
207 
208  /* Check the compressed buffer is valid */
210  return AVERROR_INVALIDDATA;
211 
212  /* Chunks are unpacked sequentially, ctx->tex_size is the uncompressed
213  * size thus far */
214  chunk->uncompressed_offset = ctx->tex_size;
215 
216  /* Fill out uncompressed size */
217  if (chunk->compressor == HAP_COMP_SNAPPY) {
218  GetByteContext gbc_tmp;
219  int64_t uncompressed_size;
220  bytestream2_init(&gbc_tmp, gbc->buffer + chunk->compressed_offset,
221  chunk->compressed_size);
222  uncompressed_size = ff_snappy_peek_uncompressed_length(&gbc_tmp);
223  if (uncompressed_size < 0) {
224  return uncompressed_size;
225  }
226  chunk->uncompressed_size = uncompressed_size;
227  } else if (chunk->compressor == HAP_COMP_NONE) {
228  chunk->uncompressed_size = chunk->compressed_size;
229  } else {
230  return AVERROR_INVALIDDATA;
231  }
232  ctx->tex_size += chunk->uncompressed_size;
233  }
234 
235  av_log(avctx, AV_LOG_DEBUG, "%s compressor\n", compressorstr);
236 
237  return ret;
238 }
239 
240 static int decompress_chunks_thread(AVCodecContext *avctx, void *arg,
241  int chunk_nb, int thread_nb)
242 {
243  HapContext *ctx = avctx->priv_data;
244 
245  HapChunk *chunk = &ctx->chunks[chunk_nb];
246  GetByteContext gbc;
247  uint8_t *dst = ctx->tex_buf + chunk->uncompressed_offset;
248 
249  bytestream2_init(&gbc, ctx->gbc.buffer + chunk->compressed_offset, chunk->compressed_size);
250 
251  if (chunk->compressor == HAP_COMP_SNAPPY) {
252  int ret;
253  int64_t uncompressed_size = ctx->tex_size;
254 
255  /* Uncompress the frame */
256  ret = ff_snappy_uncompress(&gbc, dst, &uncompressed_size);
257  if (ret < 0) {
258  av_log(avctx, AV_LOG_ERROR, "Snappy uncompress error\n");
259  return ret;
260  }
261  } else if (chunk->compressor == HAP_COMP_NONE) {
262  bytestream2_get_buffer(&gbc, dst, chunk->compressed_size);
263  }
264 
265  return 0;
266 }
267 
269  int slice, int thread_nb)
270 {
271  HapContext *ctx = avctx->priv_data;
272  AVFrame *frame = arg;
273  const uint8_t *d = ctx->tex_data;
274  int w_block = avctx->coded_width / TEXTURE_BLOCK_W;
275  int h_block = avctx->coded_height / TEXTURE_BLOCK_H;
276  int x, y;
277  int start_slice, end_slice;
278  int base_blocks_per_slice = h_block / ctx->slice_count;
279  int remainder_blocks = h_block % ctx->slice_count;
280 
281  /* When the frame height (in blocks) doesn't divide evenly between the
282  * number of slices, spread the remaining blocks evenly between the first
283  * operations */
284  start_slice = slice * base_blocks_per_slice;
285  /* Add any extra blocks (one per slice) that have been added before this slice */
286  start_slice += FFMIN(slice, remainder_blocks);
287 
288  end_slice = start_slice + base_blocks_per_slice;
289  /* Add an extra block if there are still remainder blocks to be accounted for */
290  if (slice < remainder_blocks)
291  end_slice++;
292 
293  for (y = start_slice; y < end_slice; y++) {
294  uint8_t *p = frame->data[0] + y * frame->linesize[0] * TEXTURE_BLOCK_H;
295  int off = y * w_block;
296  for (x = 0; x < w_block; x++) {
297  ctx->tex_fun(p + x * 16, frame->linesize[0],
298  d + (off + x) * ctx->tex_rat);
299  }
300  }
301 
302  return 0;
303 }
304 
305 static int hap_decode(AVCodecContext *avctx, void *data,
306  int *got_frame, AVPacket *avpkt)
307 {
308  HapContext *ctx = avctx->priv_data;
309  ThreadFrame tframe;
310  int ret, i;
311  int tex_size;
312 
313  bytestream2_init(&ctx->gbc, avpkt->data, avpkt->size);
314 
315  /* Check for section header */
316  ret = hap_parse_frame_header(avctx);
317  if (ret < 0)
318  return ret;
319 
320  /* Get the output frame ready to receive data */
321  tframe.f = data;
322  ret = ff_thread_get_buffer(avctx, &tframe, 0);
323  if (ret < 0)
324  return ret;
325  if (avctx->codec->update_thread_context)
326  ff_thread_finish_setup(avctx);
327 
328  /* Unpack the DXT texture */
329  if (hap_can_use_tex_in_place(ctx)) {
330  /* Only DXTC texture compression in a contiguous block */
331  ctx->tex_data = ctx->gbc.buffer;
332  tex_size = bytestream2_get_bytes_left(&ctx->gbc);
333  } else {
334  /* Perform the second-stage decompression */
335  ret = av_reallocp(&ctx->tex_buf, ctx->tex_size);
336  if (ret < 0)
337  return ret;
338 
339  avctx->execute2(avctx, decompress_chunks_thread, NULL,
340  ctx->chunk_results, ctx->chunk_count);
341 
342  for (i = 0; i < ctx->chunk_count; i++) {
343  if (ctx->chunk_results[i] < 0)
344  return ctx->chunk_results[i];
345  }
346 
347  ctx->tex_data = ctx->tex_buf;
348  tex_size = ctx->tex_size;
349  }
350 
351  if (tex_size < (avctx->coded_width / TEXTURE_BLOCK_W)
352  *(avctx->coded_height / TEXTURE_BLOCK_H)
353  *ctx->tex_rat) {
354  av_log(avctx, AV_LOG_ERROR, "Insufficient data\n");
355  return AVERROR_INVALIDDATA;
356  }
357 
358  /* Use the decompress function on the texture, one block per thread */
359  avctx->execute2(avctx, decompress_texture_thread, tframe.f, NULL, ctx->slice_count);
360 
361  /* Frame is ready to be output */
362  tframe.f->pict_type = AV_PICTURE_TYPE_I;
363  tframe.f->key_frame = 1;
364  *got_frame = 1;
365 
366  return avpkt->size;
367 }
368 
369 static av_cold int hap_init(AVCodecContext *avctx)
370 {
371  HapContext *ctx = avctx->priv_data;
372  const char *texture_name;
373  int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
374 
375  if (ret < 0) {
376  av_log(avctx, AV_LOG_ERROR, "Invalid video size %dx%d.\n",
377  avctx->width, avctx->height);
378  return ret;
379  }
380 
381  /* Since codec is based on 4x4 blocks, size is aligned to 4 */
382  avctx->coded_width = FFALIGN(avctx->width, TEXTURE_BLOCK_W);
383  avctx->coded_height = FFALIGN(avctx->height, TEXTURE_BLOCK_H);
384 
385  ff_texturedsp_init(&ctx->dxtc);
386 
387  switch (avctx->codec_tag) {
388  case MKTAG('H','a','p','1'):
389  texture_name = "DXT1";
390  ctx->tex_rat = 8;
391  ctx->tex_fun = ctx->dxtc.dxt1_block;
392  avctx->pix_fmt = AV_PIX_FMT_RGB0;
393  break;
394  case MKTAG('H','a','p','5'):
395  texture_name = "DXT5";
396  ctx->tex_rat = 16;
397  ctx->tex_fun = ctx->dxtc.dxt5_block;
398  avctx->pix_fmt = AV_PIX_FMT_RGBA;
399  break;
400  case MKTAG('H','a','p','Y'):
401  texture_name = "DXT5-YCoCg-scaled";
402  ctx->tex_rat = 16;
403  ctx->tex_fun = ctx->dxtc.dxt5ys_block;
404  avctx->pix_fmt = AV_PIX_FMT_RGB0;
405  break;
406  default:
408  }
409 
410  av_log(avctx, AV_LOG_DEBUG, "%s texture\n", texture_name);
411 
412  ctx->slice_count = av_clip(avctx->thread_count, 1,
413  avctx->coded_height / TEXTURE_BLOCK_H);
414 
415  return 0;
416 }
417 
418 static av_cold int hap_close(AVCodecContext *avctx)
419 {
420  HapContext *ctx = avctx->priv_data;
421 
422  ff_hap_free_context(ctx);
423 
424  return 0;
425 }
426 
428  .name = "hap",
429  .long_name = NULL_IF_CONFIG_SMALL("Vidvox Hap decoder"),
430  .type = AVMEDIA_TYPE_VIDEO,
431  .id = AV_CODEC_ID_HAP,
432  .init = hap_init,
433  .decode = hap_decode,
434  .close = hap_close,
435  .priv_data_size = sizeof(HapContext),
438  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
440 };
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: internal.h:48
Definition: hap.h:60
#define NULL
Definition: coverity.c:32
const struct AVCodec * codec
Definition: avcodec.h:1685
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:184
HapChunk * chunks
Definition: hap.h:70
static int hap_can_use_tex_in_place(HapContext *ctx)
Definition: hapdec.c:138
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
int coded_width
Bitstream width / height, may be different from width/height e.g.
Definition: avcodec.h:1878
HapSectionType
Definition: hap.h:45
int(* dxt1_block)(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Definition: texturedsp.h:46
misc image utilities
AVFrame * f
Definition: thread.h:36
int(* tex_fun)(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Definition: hap.h:83
Texture block (4x4) module.
int size
Definition: avcodec.h:1602
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1904
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
size_t compressed_size
Definition: hap.h:55
int compressed_offset
Definition: hap.h:54
AVCodec.
Definition: avcodec.h:3600
size_t uncompressed_size
Definition: hap.h:57
int64_t ff_snappy_peek_uncompressed_length(GetByteContext *gb)
Get the uncompressed length of an input buffer compressed using the Snappy algorithm.
Definition: snappy.c:131
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:40
uint8_t
#define av_cold
Definition: attributes.h:82
packed RGB 8:8:8, 32bpp, RGBXRGBX... X=unused/undefined
Definition: pixfmt.h:252
static int hap_parse_decode_instructions(HapContext *ctx, int size)
Definition: hapdec.c:69
Multithreading support functions.
AVCodec ff_hap_decoder
Definition: hapdec.c:427
int ff_hap_set_chunk_count(HapContext *ctx, int count, int first_in_frame)
Definition: hap.c:28
static AVFrame * frame
#define TEXTURE_BLOCK_H
Definition: texturedsp.h:43
TextureDSPContext dxtc
Definition: hap.h:63
uint8_t * data
Definition: avcodec.h:1601
const uint8_t * buffer
Definition: bytestream.h:34
static av_cold int hap_init(AVCodecContext *avctx)
Definition: hapdec.c:369
ptrdiff_t size
Definition: opengl_enc.c:101
void ff_thread_finish_setup(AVCodecContext *avctx)
If the codec defines update_thread_context(), call this when they are ready for the next thread to st...
#define FFALIGN(x, a)
Definition: macros.h:48
GetByteContext gbc
Definition: hap.h:64
#define av_log(a,...)
static int hap_decode(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: hapdec.c:305
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
int * chunk_results
Definition: hap.h:71
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:263
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:154
const char * arg
Definition: jacosubdec.c:66
const char * name
Name of the codec implementation.
Definition: avcodec.h:3607
int(* dxt5_block)(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Definition: texturedsp.h:51
#define AV_CODEC_CAP_FRAME_THREADS
Codec supports frame-level multithreading.
Definition: avcodec.h:1022
int ff_snappy_uncompress(GetByteContext *gb, uint8_t *buf, int64_t *size)
Decompress an input buffer using Snappy algorithm.
Definition: snappy.c:141
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:94
static av_cold int hap_close(AVCodecContext *avctx)
Definition: hapdec.c:418
int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
Check if the given dimension of an image is valid, meaning that all bytes of the image can be address...
Definition: imgutils.c:251
av_cold void ff_texturedsp_init(TextureDSPContext *c)
Definition: texturedsp.c:599
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:258
int uncompressed_offset
Definition: hap.h:56
#define FFMIN(a, b)
Definition: common.h:96
int width
picture width / height.
Definition: avcodec.h:1863
static int parse_section_header(GetByteContext *gbc, int *section_size, enum HapSectionType *section_type)
Definition: hapdec.c:47
AVFormatContext * ctx
Definition: movenc.c:48
int tex_rat
Definition: hap.h:73
int thread_count
thread count is used to decide how many independent tasks should be passed to execute() ...
Definition: avcodec.h:3107
Snappy decompression.
#define AV_CODEC_CAP_SLICE_THREADS
Codec supports slice-based (or partition-based) multithreading.
Definition: avcodec.h:1026
int av_reallocp(void *ptr, size_t size)
Allocate, reallocate, or free a block of memory through a pointer to a pointer.
Definition: mem.c:187
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:215
int ff_thread_get_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags)
Wrapper around get_buffer() for frame-multithreaded codecs.
av_cold void ff_hap_free_context(HapContext *ctx)
Definition: hap.c:50
main external API structure.
Definition: avcodec.h:1676
const uint8_t * tex_data
Definition: hap.h:74
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:1708
int chunk_count
Definition: hap.h:69
int coded_height
Definition: avcodec.h:1878
int slice_count
Definition: hap.h:80
static int decompress_chunks_thread(AVCodecContext *avctx, void *arg, int chunk_nb, int thread_nb)
Definition: hapdec.c:240
static int hap_parse_frame_header(AVCodecContext *avctx)
Definition: hapdec.c:151
static int decompress_texture_thread(AVCodecContext *avctx, void *arg, int slice, int thread_nb)
Definition: hapdec.c:268
uint8_t * tex_buf
Definition: hap.h:75
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:198
common internal api header.
size_t tex_size
Definition: hap.h:76
Definition: hap.h:52
void * priv_data
Definition: avcodec.h:1718
int(* update_thread_context)(AVCodecContext *dst, const AVCodecContext *src)
Copy necessary context variables from a previous thread context to the current one.
Definition: avcodec.h:3655
#define AVERROR_DECODER_NOT_FOUND
Decoder not found.
Definition: error.h:52
int(* execute2)(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count)
The codec may call this to execute several independent things.
Definition: avcodec.h:3167
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:253
enum HapCompressor compressor
Definition: hap.h:53
#define MKTAG(a, b, c, d)
Definition: common.h:342
#define TEXTURE_BLOCK_W
Definition: texturedsp.h:42
This structure stores compressed data.
Definition: avcodec.h:1578
int(* dxt5ys_block)(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Definition: texturedsp.h:53
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:959