FFmpeg
nuv.c
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1 /*
2  * NuppelVideo decoder
3  * Copyright (c) 2006 Reimar Doeffinger
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include <stddef.h>
23 #include <limits.h>
24 
25 #include "libavutil/common.h"
26 #include "libavutil/intreadwrite.h"
27 #include "libavutil/lzo.h"
28 #include "libavutil/imgutils.h"
29 #include "libavutil/mem.h"
30 #include "avcodec.h"
31 #include "codec_internal.h"
32 #include "decode.h"
33 #include "jpegquanttables.h"
34 #include "rtjpeg.h"
35 
36 typedef struct NuvContext {
39  int quality;
40  int width, height;
41  unsigned int decomp_size;
42  unsigned char *decomp_buf;
43  uint32_t lq[64], cq[64];
45 } NuvContext;
46 
47 /**
48  * @brief copy frame data from buffer to AVFrame, handling stride.
49  * @param f destination AVFrame
50  * @param src source buffer, does not use any line-stride
51  * @param width width of the video frame
52  * @param height height of the video frame
53  */
54 static void copy_frame(AVFrame *f, const uint8_t *src, int width, int height)
55 {
56  uint8_t *src_data[4];
57  int src_linesize[4];
58  av_image_fill_arrays(src_data, src_linesize, src,
59  f->format, width, height, 1);
60  av_image_copy2(f->data, f->linesize, src_data, src_linesize,
61  f->format, width, height);
62 }
63 
64 /**
65  * @brief extract quantization tables from codec data into our context
66  */
67 static int get_quant(AVCodecContext *avctx, NuvContext *c, const uint8_t *buf,
68  int size)
69 {
70  int i;
71  if (size < 2 * 64 * 4) {
72  av_log(avctx, AV_LOG_ERROR, "insufficient rtjpeg quant data\n");
73  return AVERROR_INVALIDDATA;
74  }
75  for (i = 0; i < 64; i++, buf += 4)
76  c->lq[i] = AV_RL32(buf);
77  for (i = 0; i < 64; i++, buf += 4)
78  c->cq[i] = AV_RL32(buf);
79  return 0;
80 }
81 
82 /**
83  * @brief set quantization tables from a quality value
84  */
86 {
87  int i;
88  quality = FFMAX(quality, 1);
89  for (i = 0; i < 64; i++) {
90  c->lq[i] = (ff_mjpeg_std_luminance_quant_tbl[i] << 7) / quality;
92  }
93 }
94 
95 static int codec_reinit(AVCodecContext *avctx, int width, int height,
96  int quality)
97 {
98  NuvContext *c = avctx->priv_data;
99  int ret;
100 
101  width = FFALIGN(width, 2);
102  height = FFALIGN(height, 2);
103  if (quality >= 0)
105  if (width != c->width || height != c->height) {
106  // also reserve space for a possible additional header
107  int64_t buf_size = height * (int64_t)width * 3 / 2
110  if (buf_size > INT_MAX/8)
111  return -1;
112  if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
113  return ret;
114  c->width = width;
115  c->height = height;
116  av_fast_malloc(&c->decomp_buf, &c->decomp_size,
117  buf_size);
118  if (!c->decomp_buf) {
119  av_log(avctx, AV_LOG_ERROR,
120  "Can't allocate decompression buffer.\n");
121  return AVERROR(ENOMEM);
122  }
123  ff_rtjpeg_decode_init(&c->rtj, c->width, c->height, c->lq, c->cq);
124  av_frame_unref(c->pic);
125  return 1;
126  } else if (quality != c->quality)
127  ff_rtjpeg_decode_init(&c->rtj, c->width, c->height, c->lq, c->cq);
128 
129  return 0;
130 }
131 
132 static int decode_frame(AVCodecContext *avctx, AVFrame *picture,
133  int *got_frame, AVPacket *avpkt)
134 {
135  const uint8_t *buf = avpkt->data;
136  int buf_size = avpkt->size;
137  NuvContext *c = avctx->priv_data;
138  int orig_size = buf_size;
139  int keyframe, ret;
140  int size_change = 0;
141  int minsize = 0;
142  int flags = 0;
143  int result, init_frame = !avctx->frame_num;
144  enum {
145  NUV_UNCOMPRESSED = '0',
146  NUV_RTJPEG = '1',
147  NUV_RTJPEG_IN_LZO = '2',
148  NUV_LZO = '3',
149  NUV_BLACK = 'N',
150  NUV_COPY_LAST = 'L'
151  } comptype;
152 
153  if (buf_size < 12) {
154  av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
155  return AVERROR_INVALIDDATA;
156  }
157 
158  // codec data (rtjpeg quant tables)
159  if (buf[0] == 'D' && buf[1] == 'R') {
160  int ret;
161  // Skip the rest of the frame header.
162  buf = &buf[12];
163  buf_size -= 12;
164  ret = get_quant(avctx, c, buf, buf_size);
165  if (ret < 0)
166  return ret;
167  ff_rtjpeg_decode_init(&c->rtj, c->width, c->height, c->lq, c->cq);
168  return orig_size;
169  }
170 
171  if (buf_size < 12 || buf[0] != 'V') {
172  av_log(avctx, AV_LOG_ERROR, "not a nuv video frame\n");
173  return AVERROR_INVALIDDATA;
174  }
175  comptype = buf[1];
176  switch (comptype) {
177  case NUV_RTJPEG_IN_LZO:
178  case NUV_RTJPEG:
179  keyframe = !buf[2];
180  if (c->width < 16 || c->height < 16) {
181  return AVERROR_INVALIDDATA;
182  }
183  break;
184  case NUV_COPY_LAST:
186  keyframe = 0;
187  break;
188  default:
189  keyframe = 1;
190  break;
191  }
192  switch (comptype) {
193  case NUV_UNCOMPRESSED:
194  minsize = c->width * c->height * 3 / 2;
195  break;
196  case NUV_RTJPEG:
197  minsize = c->width/16 * (c->height/16) * 6;
198  break;
199  case NUV_BLACK:
200  case NUV_COPY_LAST:
201  case NUV_LZO:
202  case NUV_RTJPEG_IN_LZO:
203  break;
204  default:
205  av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
206  return AVERROR_INVALIDDATA;
207  }
208  if (buf_size < minsize / 4)
209  return AVERROR_INVALIDDATA;
210 retry:
211  // Skip the rest of the frame header.
212  buf = &buf[12];
213  buf_size -= 12;
214  if (comptype == NUV_RTJPEG_IN_LZO || comptype == NUV_LZO) {
215  int outlen = c->decomp_size - FFMAX(AV_INPUT_BUFFER_PADDING_SIZE, AV_LZO_OUTPUT_PADDING);
216  int inlen = buf_size;
217  if (av_lzo1x_decode(c->decomp_buf, &outlen, buf, &inlen)) {
218  av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
219  return AVERROR_INVALIDDATA;
220  }
221  buf = c->decomp_buf;
222  buf_size = c->decomp_size - FFMAX(AV_INPUT_BUFFER_PADDING_SIZE, AV_LZO_OUTPUT_PADDING) - outlen;
223  memset(c->decomp_buf + buf_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
224  }
225  if (c->codec_frameheader) {
226  int w, h, q;
227  if (buf_size < RTJPEG_HEADER_SIZE) {
228  av_log(avctx, AV_LOG_ERROR, "Too small NUV video frame\n");
229  return AVERROR_INVALIDDATA;
230  }
231  // There seem to exist two variants of this header: one starts with 'V'
232  // and 5 bytes unknown, the other matches current MythTV and is 4 bytes size,
233  // 1 byte header size (== 12), 1 byte version (== 0)
234  if (buf[0] != 'V' && AV_RL16(&buf[4]) != 0x000c) {
235  av_log(avctx, AV_LOG_ERROR, "Unknown secondary frame header (wrong codec_tag?)\n");
236  return AVERROR_INVALIDDATA;
237  }
238  w = AV_RL16(&buf[6]);
239  h = AV_RL16(&buf[8]);
240  q = buf[10];
241  if ((result = codec_reinit(avctx, w, h, q)) < 0)
242  return result;
243  if (result) {
244  buf = avpkt->data;
245  buf_size = avpkt->size;
246  size_change = 1;
247  goto retry;
248  }
249  buf = &buf[RTJPEG_HEADER_SIZE];
250  buf_size -= RTJPEG_HEADER_SIZE;
251  }
252 
253  if (size_change || keyframe) {
254  av_frame_unref(c->pic);
255  init_frame = 1;
256  }
257 
258  if ((result = ff_reget_buffer(avctx, c->pic, flags)) < 0)
259  return result;
260  if (init_frame) {
261  memset(c->pic->data[0], 0, avctx->height * c->pic->linesize[0]);
262  memset(c->pic->data[1], 0x80, avctx->height * c->pic->linesize[1] / 2);
263  memset(c->pic->data[2], 0x80, avctx->height * c->pic->linesize[2] / 2);
264  }
265 
266  c->pic->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
267  if (keyframe)
268  c->pic->flags |= AV_FRAME_FLAG_KEY;
269  else
270  c->pic->flags &= ~AV_FRAME_FLAG_KEY;
271  // decompress/copy/whatever data
272  switch (comptype) {
273  case NUV_LZO:
274  case NUV_UNCOMPRESSED: {
275  int height = c->height;
276  if (buf_size < c->width * height * 3 / 2) {
277  av_log(avctx, AV_LOG_ERROR, "uncompressed frame too short\n");
278  height = buf_size / c->width / 3 * 2;
279  }
280  if(height > 0)
281  copy_frame(c->pic, buf, c->width, height);
282  break;
283  }
284  case NUV_RTJPEG_IN_LZO:
285  case NUV_RTJPEG:
286  ret = ff_rtjpeg_decode_frame_yuv420(&c->rtj, c->pic, buf, buf_size);
287  if (ret < 0)
288  return ret;
289  break;
290  case NUV_BLACK:
291  memset(c->pic->data[0], 0, c->width * c->height);
292  memset(c->pic->data[1], 128, c->width * c->height / 4);
293  memset(c->pic->data[2], 128, c->width * c->height / 4);
294  break;
295  case NUV_COPY_LAST:
296  /* nothing more to do here */
297  break;
298  }
299 
300  if ((result = av_frame_ref(picture, c->pic)) < 0)
301  return result;
302 
303  *got_frame = 1;
304  return orig_size;
305 }
306 
308 {
309  NuvContext *c = avctx->priv_data;
310  int ret;
311 
312  c->pic = av_frame_alloc();
313  if (!c->pic)
314  return AVERROR(ENOMEM);
315 
316  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
317  c->decomp_buf = NULL;
318  c->quality = -1;
319  c->width = 0;
320  c->height = 0;
321 
322  c->codec_frameheader = avctx->codec_tag == MKTAG('R', 'J', 'P', 'G');
323 
324  if (avctx->extradata_size)
325  get_quant(avctx, c, avctx->extradata, avctx->extradata_size);
326 
327  ff_rtjpeg_init(&c->rtj, avctx);
328 
329  if ((ret = codec_reinit(avctx, avctx->width, avctx->height, -1)) < 0)
330  return ret;
331 
332  return 0;
333 }
334 
336 {
337  NuvContext *c = avctx->priv_data;
338 
339  av_freep(&c->decomp_buf);
340  av_frame_free(&c->pic);
341 
342  return 0;
343 }
344 
346  .p.name = "nuv",
347  CODEC_LONG_NAME("NuppelVideo/RTJPEG"),
348  .p.type = AVMEDIA_TYPE_VIDEO,
349  .p.id = AV_CODEC_ID_NUV,
350  .priv_data_size = sizeof(NuvContext),
351  .init = decode_init,
352  .close = decode_end,
354  .p.capabilities = AV_CODEC_CAP_DR1,
355  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
356 };
FF_CODEC_CAP_INIT_CLEANUP
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: codec_internal.h:43
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
NuvContext::codec_frameheader
int codec_frameheader
Definition: nuv.c:38
NuvContext::cq
uint32_t cq[64]
Definition: nuv.c:43
int64_t
long long int64_t
Definition: coverity.c:34
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:162
copy_frame
static void copy_frame(AVFrame *f, const uint8_t *src, int width, int height)
copy frame data from buffer to AVFrame, handling stride.
Definition: nuv.c:54
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:389
w
uint8_t w
Definition: llviddspenc.c:38
NuvContext::width
int width
Definition: nuv.c:40
AVPacket::data
uint8_t * data
Definition: packet.h:539
codec_reinit
static int codec_reinit(AVCodecContext *avctx, int width, int height, int quality)
Definition: nuv.c:95
FFCodec
Definition: codec_internal.h:127
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
ff_set_dimensions
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:94
quality
trying all byte sequences megabyte in length and selecting the best looking sequence will yield cases to try But a word about quality
Definition: rate_distortion.txt:12
RTJPEG_HEADER_SIZE
#define RTJPEG_HEADER_SIZE
Definition: rtjpeg.h:32
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
NuvContext::quality
int quality
Definition: nuv.c:39
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *picture, int *got_frame, AVPacket *avpkt)
Definition: nuv.c:132
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:150
ff_rtjpeg_decode_init
void ff_rtjpeg_decode_init(RTJpegContext *c, int width, int height, const uint32_t *lquant, const uint32_t *cquant)
initialize an RTJpegContext, may be called multiple times
Definition: rtjpeg.c:158
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:209
av_cold
#define av_cold
Definition: attributes.h:90
AV_FRAME_FLAG_KEY
#define AV_FRAME_FLAG_KEY
A flag to mark frames that are keyframes.
Definition: frame.h:640
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:530
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:311
intreadwrite.h
AV_CODEC_ID_NUV
@ AV_CODEC_ID_NUV
Definition: codec_id.h:136
NuvContext
Definition: nuv.c:36
get_quant
static int get_quant(AVCodecContext *avctx, NuvContext *c, const uint8_t *buf, int size)
extract quantization tables from codec data into our context
Definition: nuv.c:67
decode.h
limits.h
AV_RL16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:94
NuvContext::decomp_buf
unsigned char * decomp_buf
Definition: nuv.c:42
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:73
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:296
result
and forward the result(frame or status change) to the corresponding input. If nothing is possible
NULL
#define NULL
Definition: coverity.c:32
ff_nuv_decoder
const FFCodec ff_nuv_decoder
Definition: nuv.c:345
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:279
ff_rtjpeg_decode_frame_yuv420
int ff_rtjpeg_decode_frame_yuv420(RTJpegContext *c, AVFrame *f, const uint8_t *buf, int buf_size)
decode one rtjpeg YUV420 frame
Definition: rtjpeg.c:106
jpegquanttables.h
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: nuv.c:335
f
f
Definition: af_crystalizer.c:122
av_lzo1x_decode
int av_lzo1x_decode(void *out, int *outlen, const void *in, int *inlen)
Decodes LZO 1x compressed data.
Definition: lzo.c:136
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:368
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:540
av_image_fill_arrays
int av_image_fill_arrays(uint8_t *dst_data[4], int dst_linesize[4], const uint8_t *src, enum AVPixelFormat pix_fmt, int width, int height, int align)
Setup the data pointers and linesizes based on the specified image parameters and the provided array.
Definition: imgutils.c:446
height
#define height
Definition: dsp.h:85
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:388
codec_internal.h
size
int size
Definition: twinvq_data.h:10344
get_quant_quality
static void get_quant_quality(NuvContext *c, int quality)
set quantization tables from a quality value
Definition: nuv.c:85
NuvContext::decomp_size
unsigned int decomp_size
Definition: nuv.c:41
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
AV_LZO_OUTPUT_PADDING
#define AV_LZO_OUTPUT_PADDING
Definition: lzo.h:47
AVCodecContext::extradata
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:529
common.h
ff_mjpeg_std_chrominance_quant_tbl
const uint8_t ff_mjpeg_std_chrominance_quant_tbl[64]
Definition: jpegquanttables.c:45
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:610
ff_rtjpeg_init
void ff_rtjpeg_init(RTJpegContext *c, struct AVCodecContext *avctx)
Definition: rtjpeg.c:170
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
AVCodecContext::height
int height
Definition: avcodec.h:624
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:663
NuvContext::lq
uint32_t lq[64]
Definition: nuv.c:43
avcodec.h
AVCodecContext::frame_num
int64_t frame_num
Frame counter, set by libavcodec.
Definition: avcodec.h:2041
ff_reget_buffer
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available.
Definition: decode.c:1810
ret
ret
Definition: filter_design.txt:187
NuvContext::pic
AVFrame * pic
Definition: nuv.c:37
lzo.h
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: defs.h:40
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
ff_mjpeg_std_luminance_quant_tbl
const uint8_t ff_mjpeg_std_luminance_quant_tbl[64]
Definition: jpegquanttables.c:35
AVCodecContext
main external API structure.
Definition: avcodec.h:451
av_image_copy2
static void av_image_copy2(uint8_t *const dst_data[4], const int dst_linesizes[4], uint8_t *const src_data[4], const int src_linesizes[4], enum AVPixelFormat pix_fmt, int width, int height)
Wrapper around av_image_copy() to workaround the limitation that the conversion from uint8_t * const ...
Definition: imgutils.h:184
rtjpeg.h
NuvContext::rtj
RTJpegContext rtj
Definition: nuv.c:44
init_frame
static void init_frame(FlacEncodeContext *s, int nb_samples)
Definition: flacenc.c:479
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:280
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
mem.h
AVCodecContext::codec_tag
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:476
FFALIGN
#define FFALIGN(x, a)
Definition: macros.h:78
AVPacket
This structure stores compressed data.
Definition: packet.h:516
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:478
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
av_fast_malloc
void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size)
Allocate a buffer, reusing the given one if large enough.
Definition: mem.c:557
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: nuv.c:307
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:624
imgutils.h
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:482
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
NuvContext::height
int height
Definition: nuv.c:40
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
h
h
Definition: vp9dsp_template.c:2070
width
#define width
Definition: dsp.h:85
RTJpegContext
Definition: rtjpeg.h:34
FF_REGET_BUFFER_FLAG_READONLY
#define FF_REGET_BUFFER_FLAG_READONLY
the returned buffer does not need to be writable
Definition: decode.h:128
src
#define src
Definition: vp8dsp.c:248