FFmpeg
yuv4mpegenc.c
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1 /*
2  * YUV4MPEG muxer
3  * Copyright (c) 2001, 2002, 2003 Fabrice Bellard
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 "libavutil/pixdesc.h"
23 #include "avformat.h"
24 #include "internal.h"
25 #include "yuv4mpeg.h"
26 
27 #define Y4M_LINE_MAX 256
28 
29 static int yuv4_generate_header(AVFormatContext *s, char* buf)
30 {
31  AVStream *st;
32  int width, height;
33  int raten, rated, aspectn, aspectd, n;
34  char inter;
35  const char *colorspace = "";
36  const char *colorrange = "";
37  int field_order;
38 
39  st = s->streams[0];
40  width = st->codecpar->width;
41  height = st->codecpar->height;
42  field_order = st->codecpar->field_order;
43 
44  // TODO: should be avg_frame_rate
45  av_reduce(&raten, &rated, st->time_base.den,
46  st->time_base.num, (1UL << 31) - 1);
47 
48  aspectn = st->sample_aspect_ratio.num;
49  aspectd = st->sample_aspect_ratio.den;
50 
51  if (aspectn == 0 && aspectd == 1)
52  aspectd = 0; // 0:0 means unknown
53 
54 #if FF_API_LAVF_AVCTX
55  FF_DISABLE_DEPRECATION_WARNINGS
56  if (field_order != st->codec->field_order && st->codec->field_order != AV_FIELD_UNKNOWN)
57  field_order = st->codec->field_order;
58  FF_ENABLE_DEPRECATION_WARNINGS
59 #endif
60 
61  switch(st->codecpar->color_range) {
62  case AVCOL_RANGE_MPEG:
63  colorrange = " XCOLORRANGE=LIMITED";
64  break;
65  case AVCOL_RANGE_JPEG:
66  colorrange = " XCOLORRANGE=FULL";
67  break;
68  default:
69  break;
70  }
71 
72  switch (field_order) {
73  case AV_FIELD_TB:
74  case AV_FIELD_TT: inter = 't'; break;
75  case AV_FIELD_BT:
76  case AV_FIELD_BB: inter = 'b'; break;
77  default: inter = 'p'; break;
78  }
79 
80  switch (st->codecpar->format) {
81  case AV_PIX_FMT_GRAY8:
82  colorspace = " Cmono";
83  break;
84  case AV_PIX_FMT_GRAY9:
85  colorspace = " Cmono9";
86  break;
87  case AV_PIX_FMT_GRAY10:
88  colorspace = " Cmono10";
89  break;
90  case AV_PIX_FMT_GRAY12:
91  colorspace = " Cmono12";
92  break;
93  case AV_PIX_FMT_GRAY16:
94  colorspace = " Cmono16";
95  break;
96  case AV_PIX_FMT_YUV411P:
97  colorspace = " C411 XYSCSS=411";
98  break;
99  case AV_PIX_FMT_YUVJ420P:
100  colorspace = " C420jpeg XYSCSS=420JPEG";
101  colorrange = " XCOLORRANGE=FULL";
102  break;
103  case AV_PIX_FMT_YUVJ422P:
104  colorspace = " C422 XYSCSS=422";
105  colorrange = " XCOLORRANGE=FULL";
106  break;
107  case AV_PIX_FMT_YUVJ444P:
108  colorspace = " C444 XYSCSS=444";
109  colorrange = " XCOLORRANGE=FULL";
110  break;
111  case AV_PIX_FMT_YUV420P:
112  switch (st->codecpar->chroma_location) {
113  case AVCHROMA_LOC_TOPLEFT: colorspace = " C420paldv XYSCSS=420PALDV"; break;
114  case AVCHROMA_LOC_LEFT: colorspace = " C420mpeg2 XYSCSS=420MPEG2"; break;
115  default: colorspace = " C420jpeg XYSCSS=420JPEG"; break;
116  }
117  break;
118  case AV_PIX_FMT_YUV422P:
119  colorspace = " C422 XYSCSS=422";
120  break;
121  case AV_PIX_FMT_YUV444P:
122  colorspace = " C444 XYSCSS=444";
123  break;
124  case AV_PIX_FMT_YUV420P9:
125  colorspace = " C420p9 XYSCSS=420P9";
126  break;
127  case AV_PIX_FMT_YUV422P9:
128  colorspace = " C422p9 XYSCSS=422P9";
129  break;
130  case AV_PIX_FMT_YUV444P9:
131  colorspace = " C444p9 XYSCSS=444P9";
132  break;
133  case AV_PIX_FMT_YUV420P10:
134  colorspace = " C420p10 XYSCSS=420P10";
135  break;
136  case AV_PIX_FMT_YUV422P10:
137  colorspace = " C422p10 XYSCSS=422P10";
138  break;
139  case AV_PIX_FMT_YUV444P10:
140  colorspace = " C444p10 XYSCSS=444P10";
141  break;
142  case AV_PIX_FMT_YUV420P12:
143  colorspace = " C420p12 XYSCSS=420P12";
144  break;
145  case AV_PIX_FMT_YUV422P12:
146  colorspace = " C422p12 XYSCSS=422P12";
147  break;
148  case AV_PIX_FMT_YUV444P12:
149  colorspace = " C444p12 XYSCSS=444P12";
150  break;
151  case AV_PIX_FMT_YUV420P14:
152  colorspace = " C420p14 XYSCSS=420P14";
153  break;
154  case AV_PIX_FMT_YUV422P14:
155  colorspace = " C422p14 XYSCSS=422P14";
156  break;
157  case AV_PIX_FMT_YUV444P14:
158  colorspace = " C444p14 XYSCSS=444P14";
159  break;
160  case AV_PIX_FMT_YUV420P16:
161  colorspace = " C420p16 XYSCSS=420P16";
162  break;
163  case AV_PIX_FMT_YUV422P16:
164  colorspace = " C422p16 XYSCSS=422P16";
165  break;
166  case AV_PIX_FMT_YUV444P16:
167  colorspace = " C444p16 XYSCSS=444P16";
168  break;
169  }
170 
171  /* construct stream header, if this is the first frame */
172  n = snprintf(buf, Y4M_LINE_MAX, "%s W%d H%d F%d:%d I%c A%d:%d%s%s\n",
173  Y4M_MAGIC, width, height, raten, rated, inter,
174  aspectn, aspectd, colorspace, colorrange);
175 
176  return n;
177 }
178 
179 
180 static int yuv4_write_packet(AVFormatContext *s, AVPacket *pkt)
181 {
182  AVStream *st = s->streams[pkt->stream_index];
183  AVIOContext *pb = s->pb;
184  AVFrame *frame;
185  int* first_pkt = s->priv_data;
186  int width, height, h_chroma_shift, v_chroma_shift;
187  int i;
188  char buf2[Y4M_LINE_MAX + 1];
189  uint8_t *ptr, *ptr1, *ptr2;
190 
191  frame = (AVFrame *)pkt->data;
192 
193  /* for the first packet we have to output the header as well */
194  if (*first_pkt) {
195  *first_pkt = 0;
196  if (yuv4_generate_header(s, buf2) < 0) {
197  av_log(s, AV_LOG_ERROR,
198  "Error. YUV4MPEG stream header write failed.\n");
199  return AVERROR(EIO);
200  } else {
201  avio_write(pb, buf2, strlen(buf2));
202  }
203  }
204 
205  /* construct frame header */
206 
207  avio_printf(s->pb, "%s\n", Y4M_FRAME_MAGIC);
208 
209  width = st->codecpar->width;
210  height = st->codecpar->height;
211 
212  ptr = frame->data[0];
213 
214  switch (st->codecpar->format) {
215  case AV_PIX_FMT_GRAY8:
216  case AV_PIX_FMT_YUV411P:
217  case AV_PIX_FMT_YUV420P:
218  case AV_PIX_FMT_YUV422P:
219  case AV_PIX_FMT_YUV444P:
220  // TODO: remove YUVJ pixel formats when they are completely removed from the codebase.
221  case AV_PIX_FMT_YUVJ420P:
222  case AV_PIX_FMT_YUVJ422P:
223  case AV_PIX_FMT_YUVJ444P:
224  break;
225  case AV_PIX_FMT_GRAY9:
226  case AV_PIX_FMT_GRAY10:
227  case AV_PIX_FMT_GRAY12:
228  case AV_PIX_FMT_GRAY16:
229  case AV_PIX_FMT_YUV420P9:
230  case AV_PIX_FMT_YUV422P9:
231  case AV_PIX_FMT_YUV444P9:
232  case AV_PIX_FMT_YUV420P10:
233  case AV_PIX_FMT_YUV422P10:
234  case AV_PIX_FMT_YUV444P10:
235  case AV_PIX_FMT_YUV420P12:
236  case AV_PIX_FMT_YUV422P12:
237  case AV_PIX_FMT_YUV444P12:
238  case AV_PIX_FMT_YUV420P14:
239  case AV_PIX_FMT_YUV422P14:
240  case AV_PIX_FMT_YUV444P14:
241  case AV_PIX_FMT_YUV420P16:
242  case AV_PIX_FMT_YUV422P16:
243  case AV_PIX_FMT_YUV444P16:
244  width *= 2;
245  break;
246  default:
247  av_log(s, AV_LOG_ERROR, "The pixel format '%s' is not supported.\n",
248  av_get_pix_fmt_name(st->codecpar->format));
249  return AVERROR(EINVAL);
250  }
251 
252  for (i = 0; i < height; i++) {
253  avio_write(pb, ptr, width);
254  ptr += frame->linesize[0];
255  }
256 
257  if (st->codecpar->format != AV_PIX_FMT_GRAY8 && st->codecpar->format != AV_PIX_FMT_GRAY9 &&
258  st->codecpar->format != AV_PIX_FMT_GRAY10 && st->codecpar->format != AV_PIX_FMT_GRAY12 &&
259  st->codecpar->format != AV_PIX_FMT_GRAY16) {
260  // Adjust for smaller Cb and Cr planes
261  av_pix_fmt_get_chroma_sub_sample(st->codecpar->format, &h_chroma_shift,
262  &v_chroma_shift);
263  // Shift right, rounding up
264  width = AV_CEIL_RSHIFT(width, h_chroma_shift);
265  height = AV_CEIL_RSHIFT(height, v_chroma_shift);
266 
267  ptr1 = frame->data[1];
268  ptr2 = frame->data[2];
269  for (i = 0; i < height; i++) { /* Cb */
270  avio_write(pb, ptr1, width);
271  ptr1 += frame->linesize[1];
272  }
273  for (i = 0; i < height; i++) { /* Cr */
274  avio_write(pb, ptr2, width);
275  ptr2 += frame->linesize[2];
276  }
277  }
278 
279  return 0;
280 }
281 
282 static int yuv4_write_header(AVFormatContext *s)
283 {
284  int *first_pkt = s->priv_data;
285 
286  if (s->nb_streams != 1)
287  return AVERROR(EIO);
288 
289  if (s->streams[0]->codecpar->codec_id != AV_CODEC_ID_WRAPPED_AVFRAME) {
290  av_log(s, AV_LOG_ERROR, "ERROR: Codec not supported.\n");
291  return AVERROR_INVALIDDATA;
292  }
293 
294  switch (s->streams[0]->codecpar->format) {
295  case AV_PIX_FMT_YUV411P:
296  av_log(s, AV_LOG_WARNING, "Warning: generating rarely used 4:1:1 YUV "
297  "stream, some mjpegtools might not work.\n");
298  break;
299  case AV_PIX_FMT_GRAY8:
300  case AV_PIX_FMT_YUV420P:
301  case AV_PIX_FMT_YUV422P:
302  case AV_PIX_FMT_YUV444P:
303  // TODO: remove YUVJ pixel formats when they are completely removed from the codebase.
304  case AV_PIX_FMT_YUVJ420P:
305  case AV_PIX_FMT_YUVJ422P:
306  case AV_PIX_FMT_YUVJ444P:
307  break;
308  case AV_PIX_FMT_GRAY9:
309  case AV_PIX_FMT_GRAY10:
310  case AV_PIX_FMT_GRAY12:
311  case AV_PIX_FMT_GRAY16:
312  case AV_PIX_FMT_YUV420P9:
313  case AV_PIX_FMT_YUV422P9:
314  case AV_PIX_FMT_YUV444P9:
315  case AV_PIX_FMT_YUV420P10:
316  case AV_PIX_FMT_YUV422P10:
317  case AV_PIX_FMT_YUV444P10:
318  case AV_PIX_FMT_YUV420P12:
319  case AV_PIX_FMT_YUV422P12:
320  case AV_PIX_FMT_YUV444P12:
321  case AV_PIX_FMT_YUV420P14:
322  case AV_PIX_FMT_YUV422P14:
323  case AV_PIX_FMT_YUV444P14:
324  case AV_PIX_FMT_YUV420P16:
325  case AV_PIX_FMT_YUV422P16:
326  case AV_PIX_FMT_YUV444P16:
327  if (s->strict_std_compliance >= FF_COMPLIANCE_NORMAL) {
328  av_log(s, AV_LOG_ERROR, "'%s' is not an official yuv4mpegpipe pixel format. "
329  "Use '-strict -1' to encode to this pixel format.\n",
330  av_get_pix_fmt_name(s->streams[0]->codecpar->format));
331  return AVERROR(EINVAL);
332  }
333  av_log(s, AV_LOG_WARNING, "Warning: generating non standard YUV stream. "
334  "Mjpegtools will not work.\n");
335  break;
336  default:
337  av_log(s, AV_LOG_ERROR, "ERROR: yuv4mpeg can only handle "
338  "yuv444p, yuv422p, yuv420p, yuv411p and gray8 pixel formats. "
339  "And using 'strict -1' also yuv444p9, yuv422p9, yuv420p9, "
340  "yuv444p10, yuv422p10, yuv420p10, "
341  "yuv444p12, yuv422p12, yuv420p12, "
342  "yuv444p14, yuv422p14, yuv420p14, "
343  "yuv444p16, yuv422p16, yuv420p16, "
344  "gray9, gray10, gray12 "
345  "and gray16 pixel formats. "
346  "Use -pix_fmt to select one.\n");
347  return AVERROR(EIO);
348  }
349 
350  *first_pkt = 1;
351  return 0;
352 }
353 
354 AVOutputFormat ff_yuv4mpegpipe_muxer = {
355  .name = "yuv4mpegpipe",
356  .long_name = NULL_IF_CONFIG_SMALL("YUV4MPEG pipe"),
357  .extensions = "y4m",
358  .priv_data_size = sizeof(int),
359  .audio_codec = AV_CODEC_ID_NONE,
360  .video_codec = AV_CODEC_ID_WRAPPED_AVFRAME,
361  .write_header = yuv4_write_header,
362  .write_packet = yuv4_write_packet,
363 };
FF_ENABLE_DEPRECATION_WARNINGS
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:85
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
AVOutputFormat::name
const char * name
Definition: avformat.h:491
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
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:300
pixdesc.h
AVCOL_RANGE_JPEG
@ AVCOL_RANGE_JPEG
the normal 2^n-1 "JPEG" YUV ranges
Definition: pixfmt.h:535
AVPacket::data
uint8_t * data
Definition: packet.h:355
Y4M_MAGIC
#define Y4M_MAGIC
Definition: yuv4mpeg.h:24
AV_PIX_FMT_YUV420P10
#define AV_PIX_FMT_YUV420P10
Definition: pixfmt.h:397
AV_PIX_FMT_GRAY9
#define AV_PIX_FMT_GRAY9
Definition: pixfmt.h:377
AV_FIELD_TT
@ AV_FIELD_TT
Definition: codec_par.h:39
AV_PIX_FMT_YUV422P9
#define AV_PIX_FMT_YUV422P9
Definition: pixfmt.h:395
av_pix_fmt_get_chroma_sub_sample
int av_pix_fmt_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift)
Utility function to access log2_chroma_w log2_chroma_h from the pixel format AVPixFmtDescriptor.
Definition: pixdesc.c:2577
AV_PIX_FMT_GRAY16
#define AV_PIX_FMT_GRAY16
Definition: pixfmt.h:381
AV_FIELD_TB
@ AV_FIELD_TB
Definition: codec_par.h:41
av_reduce
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
Y4M_FRAME_MAGIC
#define Y4M_FRAME_MAGIC
Definition: yuv4mpeg.h:25
AVRational::num
int num
Numerator.
Definition: rational.h:59
yuv4_generate_header
static int yuv4_generate_header(AVFormatContext *s, char *buf)
Definition: yuv4mpegenc.c:29
AV_PIX_FMT_YUV444P10
#define AV_PIX_FMT_YUV444P10
Definition: pixfmt.h:400
yuv4_write_packet
static int yuv4_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: yuv4mpegenc.c:180
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
AV_PIX_FMT_YUV422P16
#define AV_PIX_FMT_YUV422P16
Definition: pixfmt.h:409
AV_PIX_FMT_YUVJ422P
@ AV_PIX_FMT_YUVJ422P
planar YUV 4:2:2, 16bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV422P and setting col...
Definition: pixfmt.h:79
width
#define width
s
#define s(width, name)
Definition: cbs_vp9.c:257
AV_PIX_FMT_YUV444P16
#define AV_PIX_FMT_YUV444P16
Definition: pixfmt.h:410
AV_CEIL_RSHIFT
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:58
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:126
AV_FIELD_UNKNOWN
@ AV_FIELD_UNKNOWN
Definition: codec_par.h:37
AV_PIX_FMT_YUV420P9
#define AV_PIX_FMT_YUV420P9
Definition: pixfmt.h:394
AV_PIX_FMT_YUV420P16
#define AV_PIX_FMT_YUV420P16
Definition: pixfmt.h:408
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:66
AV_CODEC_ID_WRAPPED_AVFRAME
@ AV_CODEC_ID_WRAPPED_AVFRAME
Passthrough codec, AVFrames wrapped in AVPacket.
Definition: codec_id.h:559
AV_FIELD_BT
@ AV_FIELD_BT
Definition: codec_par.h:42
AV_PIX_FMT_YUVJ444P
@ AV_PIX_FMT_YUVJ444P
planar YUV 4:4:4, 24bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV444P and setting col...
Definition: pixfmt.h:80
AV_PIX_FMT_GRAY10
#define AV_PIX_FMT_GRAY10
Definition: pixfmt.h:378
if
if(ret)
Definition: filter_design.txt:179
AVFormatContext
Format I/O context.
Definition: avformat.h:1335
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1012
AVStream::time_base
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:894
AVCHROMA_LOC_LEFT
@ AVCHROMA_LOC_LEFT
MPEG-2/4 4:2:0, H.264 default for 4:2:0.
Definition: pixfmt.h:556
AVCHROMA_LOC_TOPLEFT
@ AVCHROMA_LOC_TOPLEFT
ITU-R 601, SMPTE 274M 296M S314M(DV 4:1:1), mpeg2 4:2:2.
Definition: pixfmt.h:558
AV_PIX_FMT_YUVJ420P
@ AV_PIX_FMT_YUVJ420P
planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV420P and setting col...
Definition: pixfmt.h:78
AV_PIX_FMT_YUV422P10
#define AV_PIX_FMT_YUV422P10
Definition: pixfmt.h:398
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:74
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:188
AV_PIX_FMT_YUV422P12
#define AV_PIX_FMT_YUV422P12
Definition: pixfmt.h:402
AV_PIX_FMT_YUV444P12
#define AV_PIX_FMT_YUV444P12
Definition: pixfmt.h:404
AVStream::sample_aspect_ratio
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:927
avio_write
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:213
height
#define height
FF_COMPLIANCE_NORMAL
#define FF_COMPLIANCE_NORMAL
Definition: avcodec.h:1592
yuv4_write_header
static int yuv4_write_header(AVFormatContext *s)
Definition: yuv4mpegenc.c:282
write_packet
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:702
AV_FIELD_BB
@ AV_FIELD_BB
Definition: codec_par.h:40
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:47
AVOutputFormat
Definition: avformat.h:490
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
ff_yuv4mpegpipe_muxer
AVOutputFormat ff_yuv4mpegpipe_muxer
Definition: yuv4mpegenc.c:354
AVCodecParameters::height
int height
Definition: codec_par.h:127
uint8_t
uint8_t
Definition: audio_convert.c:194
AVCodecParameters::color_range
enum AVColorRange color_range
Video only.
Definition: codec_par.h:146
yuv4mpeg.h
AVCOL_RANGE_MPEG
@ AVCOL_RANGE_MPEG
the normal 219*2^(n-8) "MPEG" YUV ranges
Definition: pixfmt.h:534
AV_PIX_FMT_YUV444P9
#define AV_PIX_FMT_YUV444P9
Definition: pixfmt.h:396
AVCodecParameters::field_order
enum AVFieldOrder field_order
Video only.
Definition: codec_par.h:141
AVStream
Stream structure.
Definition: avformat.h:865
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
avformat.h
AV_PIX_FMT_YUV420P12
#define AV_PIX_FMT_YUV420P12
Definition: pixfmt.h:401
AVCodecParameters::chroma_location
enum AVChromaLocation chroma_location
Definition: codec_par.h:150
AV_PIX_FMT_YUV422P14
#define AV_PIX_FMT_YUV422P14
Definition: pixfmt.h:406
avio_printf
int avio_printf(AVIOContext *s, const char *fmt,...) av_printf_format(2
Writes a formatted string to the context.
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
AVRational::den
int den
Denominator.
Definition: rational.h:60
AVPacket::stream_index
int stream_index
Definition: packet.h:357
AV_PIX_FMT_YUV444P
@ AV_PIX_FMT_YUV444P
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:71
FF_DISABLE_DEPRECATION_WARNINGS
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:84
AV_PIX_FMT_YUV422P
@ AV_PIX_FMT_YUV422P
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:70
AVCodecParameters::format
int format
Definition: codec_par.h:84
AVPacket
This structure stores compressed data.
Definition: packet.h:332
AV_PIX_FMT_YUV411P
@ AV_PIX_FMT_YUV411P
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples)
Definition: pixfmt.h:73
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
Y4M_LINE_MAX
#define Y4M_LINE_MAX
Definition: yuv4mpegenc.c:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
AV_PIX_FMT_YUV444P14
#define AV_PIX_FMT_YUV444P14
Definition: pixfmt.h:407
write_header
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:346
AV_PIX_FMT_GRAY12
#define AV_PIX_FMT_GRAY12
Definition: pixfmt.h:379
int
int
Definition: ffmpeg_filter.c:192
snprintf
#define snprintf
Definition: snprintf.h:34
AV_PIX_FMT_YUV420P14
#define AV_PIX_FMT_YUV420P14
Definition: pixfmt.h:405
av_get_pix_fmt_name
const char * av_get_pix_fmt_name(enum AVPixelFormat pix_fmt)
Return the short name for a pixel format, NULL in case pix_fmt is unknown.
Definition: pixdesc.c:2465
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