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yuv4mpeg.c
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1 /*
2  * YUV4MPEG format
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 
26 #define Y4M_MAGIC "YUV4MPEG2"
27 #define Y4M_FRAME_MAGIC "FRAME"
28 #define Y4M_LINE_MAX 256
29 
30 #if CONFIG_YUV4MPEGPIPE_MUXER
31 static int yuv4_generate_header(AVFormatContext *s, char* buf)
32 {
33  AVStream *st;
34  int width, height;
35  int raten, rated, aspectn, aspectd, n;
36  char inter;
37  const char *colorspace = "";
38 
39  st = s->streams[0];
40  width = st->codec->width;
41  height = st->codec->height;
42 
43  av_reduce(&raten, &rated, st->codec->time_base.den,
44  st->codec->time_base.num, (1UL << 31) - 1);
45 
46  aspectn = st->sample_aspect_ratio.num;
47  aspectd = st->sample_aspect_ratio.den;
48 
49  if (aspectn == 0 && aspectd == 1)
50  aspectd = 0; // 0:0 means unknown
51 
52  inter = 'p'; /* progressive is the default */
53  if (st->codec->coded_frame && st->codec->coded_frame->interlaced_frame)
54  inter = st->codec->coded_frame->top_field_first ? 't' : 'b';
55  if (st->codec->field_order == AV_FIELD_PROGRESSIVE) {
56  inter = 'p';
57  } else if (st->codec->field_order == AV_FIELD_TB || st->codec->field_order == AV_FIELD_TT) {
58  inter = 't';
59  } else if (st->codec->field_order == AV_FIELD_BT || st->codec->field_order == AV_FIELD_BB) {
60  inter = 'b';
61  }
62 
63  switch (st->codec->pix_fmt) {
64  case AV_PIX_FMT_GRAY8:
65  colorspace = " Cmono";
66  break;
67  case AV_PIX_FMT_GRAY16:
68  colorspace = " Cmono16";
69  break;
70  case AV_PIX_FMT_YUV411P:
71  colorspace = " C411 XYSCSS=411";
72  break;
73  case AV_PIX_FMT_YUV420P:
74  switch (st->codec->chroma_sample_location) {
75  case AVCHROMA_LOC_TOPLEFT: colorspace = " C420paldv XYSCSS=420PALDV"; break;
76  case AVCHROMA_LOC_LEFT: colorspace = " C420mpeg2 XYSCSS=420MPEG2"; break;
77  default: colorspace = " C420jpeg XYSCSS=420JPEG"; break;
78  }
79  break;
80  case AV_PIX_FMT_YUV422P:
81  colorspace = " C422 XYSCSS=422";
82  break;
83  case AV_PIX_FMT_YUV444P:
84  colorspace = " C444 XYSCSS=444";
85  break;
86  case AV_PIX_FMT_YUV420P9:
87  colorspace = " C420p9 XYSCSS=420P9";
88  break;
89  case AV_PIX_FMT_YUV422P9:
90  colorspace = " C422p9 XYSCSS=422P9";
91  break;
92  case AV_PIX_FMT_YUV444P9:
93  colorspace = " C444p9 XYSCSS=444P9";
94  break;
95  case AV_PIX_FMT_YUV420P10:
96  colorspace = " C420p10 XYSCSS=420P10";
97  break;
98  case AV_PIX_FMT_YUV422P10:
99  colorspace = " C422p10 XYSCSS=422P10";
100  break;
101  case AV_PIX_FMT_YUV444P10:
102  colorspace = " C444p10 XYSCSS=444P10";
103  break;
104  case AV_PIX_FMT_YUV420P12:
105  colorspace = " C420p12 XYSCSS=420P12";
106  break;
107  case AV_PIX_FMT_YUV422P12:
108  colorspace = " C422p12 XYSCSS=422P12";
109  break;
110  case AV_PIX_FMT_YUV444P12:
111  colorspace = " C444p12 XYSCSS=444P12";
112  break;
113  case AV_PIX_FMT_YUV420P14:
114  colorspace = " C420p14 XYSCSS=420P14";
115  break;
116  case AV_PIX_FMT_YUV422P14:
117  colorspace = " C422p14 XYSCSS=422P14";
118  break;
119  case AV_PIX_FMT_YUV444P14:
120  colorspace = " C444p14 XYSCSS=444P14";
121  break;
122  case AV_PIX_FMT_YUV420P16:
123  colorspace = " C420p16 XYSCSS=420P16";
124  break;
125  case AV_PIX_FMT_YUV422P16:
126  colorspace = " C422p16 XYSCSS=422P16";
127  break;
128  case AV_PIX_FMT_YUV444P16:
129  colorspace = " C444p16 XYSCSS=444P16";
130  break;
131  }
132 
133  /* construct stream header, if this is the first frame */
134  n = snprintf(buf, Y4M_LINE_MAX, "%s W%d H%d F%d:%d I%c A%d:%d%s\n",
135  Y4M_MAGIC, width, height, raten, rated, inter,
136  aspectn, aspectd, colorspace);
137 
138  return n;
139 }
140 
141 static int yuv4_write_packet(AVFormatContext *s, AVPacket *pkt)
142 {
143  AVStream *st = s->streams[pkt->stream_index];
144  AVIOContext *pb = s->pb;
145  AVPicture *picture, picture_tmp;
146  int* first_pkt = s->priv_data;
147  int width, height, h_chroma_shift, v_chroma_shift;
148  int i;
149  char buf2[Y4M_LINE_MAX + 1];
150  char buf1[20];
151  uint8_t *ptr, *ptr1, *ptr2;
152 
153  memcpy(&picture_tmp, pkt->data, sizeof(AVPicture));
154  picture = &picture_tmp;
155 
156  /* for the first packet we have to output the header as well */
157  if (*first_pkt) {
158  *first_pkt = 0;
159  if (yuv4_generate_header(s, buf2) < 0) {
160  av_log(s, AV_LOG_ERROR,
161  "Error. YUV4MPEG stream header write failed.\n");
162  return AVERROR(EIO);
163  } else {
164  avio_write(pb, buf2, strlen(buf2));
165  }
166  }
167 
168  /* construct frame header */
169 
170  snprintf(buf1, sizeof(buf1), "%s\n", Y4M_FRAME_MAGIC);
171  avio_write(pb, buf1, strlen(buf1));
172 
173  width = st->codec->width;
174  height = st->codec->height;
175 
176  ptr = picture->data[0];
177 
178  switch (st->codec->pix_fmt) {
179  case AV_PIX_FMT_GRAY8:
180  case AV_PIX_FMT_YUV411P:
181  case AV_PIX_FMT_YUV420P:
182  case AV_PIX_FMT_YUV422P:
183  case AV_PIX_FMT_YUV444P:
184  break;
185  case AV_PIX_FMT_GRAY16:
186  case AV_PIX_FMT_YUV420P9:
187  case AV_PIX_FMT_YUV422P9:
188  case AV_PIX_FMT_YUV444P9:
189  case AV_PIX_FMT_YUV420P10:
190  case AV_PIX_FMT_YUV422P10:
191  case AV_PIX_FMT_YUV444P10:
192  case AV_PIX_FMT_YUV420P12:
193  case AV_PIX_FMT_YUV422P12:
194  case AV_PIX_FMT_YUV444P12:
195  case AV_PIX_FMT_YUV420P14:
196  case AV_PIX_FMT_YUV422P14:
197  case AV_PIX_FMT_YUV444P14:
198  case AV_PIX_FMT_YUV420P16:
199  case AV_PIX_FMT_YUV422P16:
200  case AV_PIX_FMT_YUV444P16:
201  width *= 2;
202  break;
203  default:
204  av_log(s, AV_LOG_ERROR, "The pixel format '%s' is not supported.\n",
205  av_get_pix_fmt_name(st->codec->pix_fmt));
206  return AVERROR(EINVAL);
207  }
208 
209  for (i = 0; i < height; i++) {
210  avio_write(pb, ptr, width);
211  ptr += picture->linesize[0];
212  }
213 
214  if (st->codec->pix_fmt != AV_PIX_FMT_GRAY8 &&
215  st->codec->pix_fmt != AV_PIX_FMT_GRAY16) {
216  // Adjust for smaller Cb and Cr planes
217  av_pix_fmt_get_chroma_sub_sample(st->codec->pix_fmt, &h_chroma_shift,
218  &v_chroma_shift);
219  width = FF_CEIL_RSHIFT(width, h_chroma_shift);
220  height = FF_CEIL_RSHIFT(height, v_chroma_shift);
221 
222  ptr1 = picture->data[1];
223  ptr2 = picture->data[2];
224  for (i = 0; i < height; i++) { /* Cb */
225  avio_write(pb, ptr1, width);
226  ptr1 += picture->linesize[1];
227  }
228  for (i = 0; i < height; i++) { /* Cr */
229  avio_write(pb, ptr2, width);
230  ptr2 += picture->linesize[2];
231  }
232  }
233 
234  return 0;
235 }
236 
237 static int yuv4_write_header(AVFormatContext *s)
238 {
239  int *first_pkt = s->priv_data;
240 
241  if (s->nb_streams != 1)
242  return AVERROR(EIO);
243 
244  if (s->streams[0]->codec->codec_id != AV_CODEC_ID_RAWVIDEO) {
245  av_log(s, AV_LOG_ERROR, "ERROR: Only rawvideo supported.\n");
246  return AVERROR_INVALIDDATA;
247  }
248 
249  switch (s->streams[0]->codec->pix_fmt) {
250  case AV_PIX_FMT_YUV411P:
251  av_log(s, AV_LOG_WARNING, "Warning: generating rarely used 4:1:1 YUV "
252  "stream, some mjpegtools might not work.\n");
253  break;
254  case AV_PIX_FMT_GRAY8:
255  case AV_PIX_FMT_GRAY16:
256  case AV_PIX_FMT_YUV420P:
257  case AV_PIX_FMT_YUV422P:
258  case AV_PIX_FMT_YUV444P:
259  break;
260  case AV_PIX_FMT_YUV420P9:
261  case AV_PIX_FMT_YUV422P9:
262  case AV_PIX_FMT_YUV444P9:
263  case AV_PIX_FMT_YUV420P10:
264  case AV_PIX_FMT_YUV422P10:
265  case AV_PIX_FMT_YUV444P10:
266  case AV_PIX_FMT_YUV420P12:
267  case AV_PIX_FMT_YUV422P12:
268  case AV_PIX_FMT_YUV444P12:
269  case AV_PIX_FMT_YUV420P14:
270  case AV_PIX_FMT_YUV422P14:
271  case AV_PIX_FMT_YUV444P14:
272  case AV_PIX_FMT_YUV420P16:
273  case AV_PIX_FMT_YUV422P16:
274  case AV_PIX_FMT_YUV444P16:
275  if (s->streams[0]->codec->strict_std_compliance >= FF_COMPLIANCE_NORMAL) {
276  av_log(s, AV_LOG_ERROR, "'%s' is not a official yuv4mpegpipe pixel format. "
277  "Use '-strict -1' to encode to this pixel format.\n",
278  av_get_pix_fmt_name(s->streams[0]->codec->pix_fmt));
279  return AVERROR(EINVAL);
280  }
281  av_log(s, AV_LOG_WARNING, "Warning: generating non standard YUV stream. "
282  "Mjpegtools will not work.\n");
283  break;
284  default:
285  av_log(s, AV_LOG_ERROR, "ERROR: yuv4mpeg can only handle "
286  "yuv444p, yuv422p, yuv420p, yuv411p and gray8 pixel formats. "
287  "And using 'strict -1' also yuv444p9, yuv422p9, yuv420p9, "
288  "yuv444p10, yuv422p10, yuv420p10, "
289  "yuv444p12, yuv422p12, yuv420p12, "
290  "yuv444p14, yuv422p14, yuv420p14, "
291  "yuv444p16, yuv422p16, yuv420p16 "
292  "and gray16 pixel formats. "
293  "Use -pix_fmt to select one.\n");
294  return AVERROR(EIO);
295  }
296 
297  *first_pkt = 1;
298  return 0;
299 }
300 
301 AVOutputFormat ff_yuv4mpegpipe_muxer = {
302  .name = "yuv4mpegpipe",
303  .long_name = NULL_IF_CONFIG_SMALL("YUV4MPEG pipe"),
304  .extensions = "y4m",
305  .priv_data_size = sizeof(int),
306  .audio_codec = AV_CODEC_ID_NONE,
307  .video_codec = AV_CODEC_ID_RAWVIDEO,
308  .write_header = yuv4_write_header,
309  .write_packet = yuv4_write_packet,
310  .flags = AVFMT_RAWPICTURE,
311 };
312 #endif
313 
314 /* Header size increased to allow room for optional flags */
315 #define MAX_YUV4_HEADER 80
316 #define MAX_FRAME_HEADER 80
317 
318 static int yuv4_read_header(AVFormatContext *s)
319 {
320  char header[MAX_YUV4_HEADER + 10]; // Include headroom for
321  // the longest option
322  char *tokstart, *tokend, *header_end, interlaced = '?';
323  int i;
324  AVIOContext *pb = s->pb;
325  int width = -1, height = -1, raten = 0,
326  rated = 0, aspectn = 0, aspectd = 0;
327  enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE, alt_pix_fmt = AV_PIX_FMT_NONE;
328  enum AVChromaLocation chroma_sample_location = AVCHROMA_LOC_UNSPECIFIED;
329  AVStream *st;
330 
331  for (i = 0; i < MAX_YUV4_HEADER; i++) {
332  header[i] = avio_r8(pb);
333  if (header[i] == '\n') {
334  header[i + 1] = 0x20; // Add a space after last option.
335  // Makes parsing "444" vs "444alpha" easier.
336  header[i + 2] = 0;
337  break;
338  }
339  }
340  if (i == MAX_YUV4_HEADER)
341  return -1;
342  if (strncmp(header, Y4M_MAGIC, strlen(Y4M_MAGIC)))
343  return -1;
344 
345  header_end = &header[i + 1]; // Include space
346  for (tokstart = &header[strlen(Y4M_MAGIC) + 1];
347  tokstart < header_end; tokstart++) {
348  if (*tokstart == 0x20)
349  continue;
350  switch (*tokstart++) {
351  case 'W': // Width. Required.
352  width = strtol(tokstart, &tokend, 10);
353  tokstart = tokend;
354  break;
355  case 'H': // Height. Required.
356  height = strtol(tokstart, &tokend, 10);
357  tokstart = tokend;
358  break;
359  case 'C': // Color space
360  if (strncmp("420jpeg", tokstart, 7) == 0) {
361  pix_fmt = AV_PIX_FMT_YUV420P;
362  chroma_sample_location = AVCHROMA_LOC_CENTER;
363  } else if (strncmp("420mpeg2", tokstart, 8) == 0) {
364  pix_fmt = AV_PIX_FMT_YUV420P;
365  chroma_sample_location = AVCHROMA_LOC_LEFT;
366  } else if (strncmp("420paldv", tokstart, 8) == 0) {
367  pix_fmt = AV_PIX_FMT_YUV420P;
368  chroma_sample_location = AVCHROMA_LOC_TOPLEFT;
369  } else if (strncmp("420p16", tokstart, 6) == 0) {
370  pix_fmt = AV_PIX_FMT_YUV420P16;
371  } else if (strncmp("422p16", tokstart, 6) == 0) {
372  pix_fmt = AV_PIX_FMT_YUV422P16;
373  } else if (strncmp("444p16", tokstart, 6) == 0) {
374  pix_fmt = AV_PIX_FMT_YUV444P16;
375  } else if (strncmp("420p14", tokstart, 6) == 0) {
376  pix_fmt = AV_PIX_FMT_YUV420P14;
377  } else if (strncmp("422p14", tokstart, 6) == 0) {
378  pix_fmt = AV_PIX_FMT_YUV422P14;
379  } else if (strncmp("444p14", tokstart, 6) == 0) {
380  pix_fmt = AV_PIX_FMT_YUV444P14;
381  } else if (strncmp("420p12", tokstart, 6) == 0) {
382  pix_fmt = AV_PIX_FMT_YUV420P12;
383  } else if (strncmp("422p12", tokstart, 6) == 0) {
384  pix_fmt = AV_PIX_FMT_YUV422P12;
385  } else if (strncmp("444p12", tokstart, 6) == 0) {
386  pix_fmt = AV_PIX_FMT_YUV444P12;
387  } else if (strncmp("420p10", tokstart, 6) == 0) {
388  pix_fmt = AV_PIX_FMT_YUV420P10;
389  } else if (strncmp("422p10", tokstart, 6) == 0) {
390  pix_fmt = AV_PIX_FMT_YUV422P10;
391  } else if (strncmp("444p10", tokstart, 6) == 0) {
392  pix_fmt = AV_PIX_FMT_YUV444P10;
393  } else if (strncmp("420p9", tokstart, 5) == 0) {
394  pix_fmt = AV_PIX_FMT_YUV420P9;
395  } else if (strncmp("422p9", tokstart, 5) == 0) {
396  pix_fmt = AV_PIX_FMT_YUV422P9;
397  } else if (strncmp("444p9", tokstart, 5) == 0) {
398  pix_fmt = AV_PIX_FMT_YUV444P9;
399  } else if (strncmp("420", tokstart, 3) == 0) {
400  pix_fmt = AV_PIX_FMT_YUV420P;
401  chroma_sample_location = AVCHROMA_LOC_CENTER;
402  } else if (strncmp("411", tokstart, 3) == 0) {
403  pix_fmt = AV_PIX_FMT_YUV411P;
404  } else if (strncmp("422", tokstart, 3) == 0) {
405  pix_fmt = AV_PIX_FMT_YUV422P;
406  } else if (strncmp("444alpha", tokstart, 8) == 0 ) {
407  av_log(s, AV_LOG_ERROR, "Cannot handle 4:4:4:4 "
408  "YUV4MPEG stream.\n");
409  return -1;
410  } else if (strncmp("444", tokstart, 3) == 0) {
411  pix_fmt = AV_PIX_FMT_YUV444P;
412  } else if (strncmp("mono16", tokstart, 6) == 0) {
413  pix_fmt = AV_PIX_FMT_GRAY16;
414  } else if (strncmp("mono", tokstart, 4) == 0) {
415  pix_fmt = AV_PIX_FMT_GRAY8;
416  } else {
417  av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains an unknown "
418  "pixel format.\n");
419  return -1;
420  }
421  while (tokstart < header_end && *tokstart != 0x20)
422  tokstart++;
423  break;
424  case 'I': // Interlace type
425  interlaced = *tokstart++;
426  break;
427  case 'F': // Frame rate
428  sscanf(tokstart, "%d:%d", &raten, &rated); // 0:0 if unknown
429  while (tokstart < header_end && *tokstart != 0x20)
430  tokstart++;
431  break;
432  case 'A': // Pixel aspect
433  sscanf(tokstart, "%d:%d", &aspectn, &aspectd); // 0:0 if unknown
434  while (tokstart < header_end && *tokstart != 0x20)
435  tokstart++;
436  break;
437  case 'X': // Vendor extensions
438  if (strncmp("YSCSS=", tokstart, 6) == 0) {
439  // Older nonstandard pixel format representation
440  tokstart += 6;
441  if (strncmp("420JPEG", tokstart, 7) == 0)
442  alt_pix_fmt = AV_PIX_FMT_YUV420P;
443  else if (strncmp("420MPEG2", tokstart, 8) == 0)
444  alt_pix_fmt = AV_PIX_FMT_YUV420P;
445  else if (strncmp("420PALDV", tokstart, 8) == 0)
446  alt_pix_fmt = AV_PIX_FMT_YUV420P;
447  else if (strncmp("420P9", tokstart, 5) == 0)
448  alt_pix_fmt = AV_PIX_FMT_YUV420P9;
449  else if (strncmp("422P9", tokstart, 5) == 0)
450  alt_pix_fmt = AV_PIX_FMT_YUV422P9;
451  else if (strncmp("444P9", tokstart, 5) == 0)
452  alt_pix_fmt = AV_PIX_FMT_YUV444P9;
453  else if (strncmp("420P10", tokstart, 6) == 0)
454  alt_pix_fmt = AV_PIX_FMT_YUV420P10;
455  else if (strncmp("422P10", tokstart, 6) == 0)
456  alt_pix_fmt = AV_PIX_FMT_YUV422P10;
457  else if (strncmp("444P10", tokstart, 6) == 0)
458  alt_pix_fmt = AV_PIX_FMT_YUV444P10;
459  else if (strncmp("420P12", tokstart, 6) == 0)
460  alt_pix_fmt = AV_PIX_FMT_YUV420P12;
461  else if (strncmp("422P12", tokstart, 6) == 0)
462  alt_pix_fmt = AV_PIX_FMT_YUV422P12;
463  else if (strncmp("444P12", tokstart, 6) == 0)
464  alt_pix_fmt = AV_PIX_FMT_YUV444P12;
465  else if (strncmp("420P14", tokstart, 6) == 0)
466  alt_pix_fmt = AV_PIX_FMT_YUV420P14;
467  else if (strncmp("422P14", tokstart, 6) == 0)
468  alt_pix_fmt = AV_PIX_FMT_YUV422P14;
469  else if (strncmp("444P14", tokstart, 6) == 0)
470  alt_pix_fmt = AV_PIX_FMT_YUV444P14;
471  else if (strncmp("420P16", tokstart, 6) == 0)
472  alt_pix_fmt = AV_PIX_FMT_YUV420P16;
473  else if (strncmp("422P16", tokstart, 6) == 0)
474  alt_pix_fmt = AV_PIX_FMT_YUV422P16;
475  else if (strncmp("444P16", tokstart, 6) == 0)
476  alt_pix_fmt = AV_PIX_FMT_YUV444P16;
477  else if (strncmp("411", tokstart, 3) == 0)
478  alt_pix_fmt = AV_PIX_FMT_YUV411P;
479  else if (strncmp("422", tokstart, 3) == 0)
480  alt_pix_fmt = AV_PIX_FMT_YUV422P;
481  else if (strncmp("444", tokstart, 3) == 0)
482  alt_pix_fmt = AV_PIX_FMT_YUV444P;
483  }
484  while (tokstart < header_end && *tokstart != 0x20)
485  tokstart++;
486  break;
487  }
488  }
489 
490  if (width == -1 || height == -1) {
491  av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");
492  return -1;
493  }
494 
495  if (pix_fmt == AV_PIX_FMT_NONE) {
496  if (alt_pix_fmt == AV_PIX_FMT_NONE)
497  pix_fmt = AV_PIX_FMT_YUV420P;
498  else
499  pix_fmt = alt_pix_fmt;
500  }
501 
502  if (raten <= 0 || rated <= 0) {
503  // Frame rate unknown
504  raten = 25;
505  rated = 1;
506  }
507 
508  if (aspectn == 0 && aspectd == 0) {
509  // Pixel aspect unknown
510  aspectd = 1;
511  }
512 
513  st = avformat_new_stream(s, NULL);
514  if (!st)
515  return AVERROR(ENOMEM);
516  st->codec->width = width;
517  st->codec->height = height;
518  av_reduce(&raten, &rated, raten, rated, (1UL << 31) - 1);
519  avpriv_set_pts_info(st, 64, rated, raten);
520  st->avg_frame_rate = av_inv_q(st->time_base);
521  st->codec->pix_fmt = pix_fmt;
522  st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
523  st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
524  st->sample_aspect_ratio = (AVRational){ aspectn, aspectd };
525  st->codec->chroma_sample_location = chroma_sample_location;
526 
527  switch (interlaced){
528  case 'p':
529  st->codec->field_order = AV_FIELD_PROGRESSIVE;
530  break;
531  case 't':
532  st->codec->field_order = AV_FIELD_TB;
533  break;
534  case 'b':
535  st->codec->field_order = AV_FIELD_BT;
536  break;
537  case 'm':
538  av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains mixed "
539  "interlaced and non-interlaced frames.\n");
540  case '?':
541  st->codec->field_order = AV_FIELD_UNKNOWN;
542  break;
543  default:
544  av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");
545  return AVERROR(EINVAL);
546  }
547 
548  return 0;
549 }
550 
551 static int yuv4_read_packet(AVFormatContext *s, AVPacket *pkt)
552 {
553  int i;
554  char header[MAX_FRAME_HEADER+1];
555  int packet_size, width, height, ret;
556  AVStream *st = s->streams[0];
557 
558  for (i = 0; i < MAX_FRAME_HEADER; i++) {
559  header[i] = avio_r8(s->pb);
560  if (header[i] == '\n') {
561  header[i + 1] = 0;
562  break;
563  }
564  }
565  if (s->pb->error)
566  return s->pb->error;
567  else if (s->pb->eof_reached)
568  return AVERROR_EOF;
569  else if (i == MAX_FRAME_HEADER)
570  return AVERROR_INVALIDDATA;
571 
572  if (strncmp(header, Y4M_FRAME_MAGIC, strlen(Y4M_FRAME_MAGIC)))
573  return AVERROR_INVALIDDATA;
574 
575  width = st->codec->width;
576  height = st->codec->height;
577 
578  packet_size = avpicture_get_size(st->codec->pix_fmt, width, height);
579  if (packet_size < 0)
580  return packet_size;
581 
582  ret = av_get_packet(s->pb, pkt, packet_size);
583  if (ret < 0)
584  return ret;
585  else if (ret != packet_size)
586  return s->pb->eof_reached ? AVERROR_EOF : AVERROR(EIO);
587 
588  pkt->stream_index = 0;
589  return 0;
590 }
591 
592 static int yuv4_probe(AVProbeData *pd)
593 {
594  /* check file header */
595  if (strncmp(pd->buf, Y4M_MAGIC, sizeof(Y4M_MAGIC) - 1) == 0)
596  return AVPROBE_SCORE_MAX;
597  else
598  return 0;
599 }
600 
601 #if CONFIG_YUV4MPEGPIPE_DEMUXER
602 AVInputFormat ff_yuv4mpegpipe_demuxer = {
603  .name = "yuv4mpegpipe",
604  .long_name = NULL_IF_CONFIG_SMALL("YUV4MPEG pipe"),
605  .read_probe = yuv4_probe,
606  .read_header = yuv4_read_header,
607  .read_packet = yuv4_read_packet,
608  .extensions = "y4m",
609 };
610 #endif
Generated on Sun Mar 23 2014 23:50:14 for FFmpeg by   doxygen 1.8.2