Don't allow to sync on packets of zero-size length, since these are never
[ffmpeg-lucabe.git] / output_example.c
blobc6cd99f7b8329b165ce02babeb5fcdd848264394
1 /*
2 * Libavformat API example: Output a media file in any supported
3 * libavformat format. The default codecs are used.
5 * Copyright (c) 2003 Fabrice Bellard
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
25 #include <stdlib.h>
26 #include <stdio.h>
27 #include <string.h>
28 #include <math.h>
30 #ifndef M_PI
31 #define M_PI 3.14159265358979323846
32 #endif
34 #include "libavformat/avformat.h"
35 #include "libswscale/swscale.h"
37 #undef exit
39 /* 5 seconds stream duration */
40 #define STREAM_DURATION 5.0
41 #define STREAM_FRAME_RATE 25 /* 25 images/s */
42 #define STREAM_NB_FRAMES ((int)(STREAM_DURATION * STREAM_FRAME_RATE))
43 #define STREAM_PIX_FMT PIX_FMT_YUV420P /* default pix_fmt */
45 static int sws_flags = SWS_BICUBIC;
47 /**************************************************************/
48 /* audio output */
50 float t, tincr, tincr2;
51 int16_t *samples;
52 uint8_t *audio_outbuf;
53 int audio_outbuf_size;
54 int audio_input_frame_size;
57 * add an audio output stream
59 static AVStream *add_audio_stream(AVFormatContext *oc, int codec_id)
61 AVCodecContext *c;
62 AVStream *st;
64 st = av_new_stream(oc, 1);
65 if (!st) {
66 fprintf(stderr, "Could not alloc stream\n");
67 exit(1);
70 c = st->codec;
71 c->codec_id = codec_id;
72 c->codec_type = CODEC_TYPE_AUDIO;
74 /* put sample parameters */
75 c->bit_rate = 64000;
76 c->sample_rate = 44100;
77 c->channels = 2;
78 return st;
81 static void open_audio(AVFormatContext *oc, AVStream *st)
83 AVCodecContext *c;
84 AVCodec *codec;
86 c = st->codec;
88 /* find the audio encoder */
89 codec = avcodec_find_encoder(c->codec_id);
90 if (!codec) {
91 fprintf(stderr, "codec not found\n");
92 exit(1);
95 /* open it */
96 if (avcodec_open(c, codec) < 0) {
97 fprintf(stderr, "could not open codec\n");
98 exit(1);
101 /* init signal generator */
102 t = 0;
103 tincr = 2 * M_PI * 110.0 / c->sample_rate;
104 /* increment frequency by 110 Hz per second */
105 tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
107 audio_outbuf_size = 10000;
108 audio_outbuf = av_malloc(audio_outbuf_size);
110 /* ugly hack for PCM codecs (will be removed ASAP with new PCM
111 support to compute the input frame size in samples */
112 if (c->frame_size <= 1) {
113 audio_input_frame_size = audio_outbuf_size / c->channels;
114 switch(st->codec->codec_id) {
115 case CODEC_ID_PCM_S16LE:
116 case CODEC_ID_PCM_S16BE:
117 case CODEC_ID_PCM_U16LE:
118 case CODEC_ID_PCM_U16BE:
119 audio_input_frame_size >>= 1;
120 break;
121 default:
122 break;
124 } else {
125 audio_input_frame_size = c->frame_size;
127 samples = av_malloc(audio_input_frame_size * 2 * c->channels);
130 /* prepare a 16 bit dummy audio frame of 'frame_size' samples and
131 'nb_channels' channels */
132 static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels)
134 int j, i, v;
135 int16_t *q;
137 q = samples;
138 for(j=0;j<frame_size;j++) {
139 v = (int)(sin(t) * 10000);
140 for(i = 0; i < nb_channels; i++)
141 *q++ = v;
142 t += tincr;
143 tincr += tincr2;
147 static void write_audio_frame(AVFormatContext *oc, AVStream *st)
149 AVCodecContext *c;
150 AVPacket pkt;
151 av_init_packet(&pkt);
153 c = st->codec;
155 get_audio_frame(samples, audio_input_frame_size, c->channels);
157 pkt.size= avcodec_encode_audio(c, audio_outbuf, audio_outbuf_size, samples);
159 if (c->coded_frame->pts != AV_NOPTS_VALUE)
160 pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base);
161 pkt.flags |= PKT_FLAG_KEY;
162 pkt.stream_index= st->index;
163 pkt.data= audio_outbuf;
165 /* write the compressed frame in the media file */
166 if (av_interleaved_write_frame(oc, &pkt) != 0) {
167 fprintf(stderr, "Error while writing audio frame\n");
168 exit(1);
172 static void close_audio(AVFormatContext *oc, AVStream *st)
174 avcodec_close(st->codec);
176 av_free(samples);
177 av_free(audio_outbuf);
180 /**************************************************************/
181 /* video output */
183 AVFrame *picture, *tmp_picture;
184 uint8_t *video_outbuf;
185 int frame_count, video_outbuf_size;
187 /* add a video output stream */
188 static AVStream *add_video_stream(AVFormatContext *oc, int codec_id)
190 AVCodecContext *c;
191 AVStream *st;
193 st = av_new_stream(oc, 0);
194 if (!st) {
195 fprintf(stderr, "Could not alloc stream\n");
196 exit(1);
199 c = st->codec;
200 c->codec_id = codec_id;
201 c->codec_type = CODEC_TYPE_VIDEO;
203 /* put sample parameters */
204 c->bit_rate = 400000;
205 /* resolution must be a multiple of two */
206 c->width = 352;
207 c->height = 288;
208 /* time base: this is the fundamental unit of time (in seconds) in terms
209 of which frame timestamps are represented. for fixed-fps content,
210 timebase should be 1/framerate and timestamp increments should be
211 identically 1. */
212 c->time_base.den = STREAM_FRAME_RATE;
213 c->time_base.num = 1;
214 c->gop_size = 12; /* emit one intra frame every twelve frames at most */
215 c->pix_fmt = STREAM_PIX_FMT;
216 if (c->codec_id == CODEC_ID_MPEG2VIDEO) {
217 /* just for testing, we also add B frames */
218 c->max_b_frames = 2;
220 if (c->codec_id == CODEC_ID_MPEG1VIDEO){
221 /* Needed to avoid using macroblocks in which some coeffs overflow.
222 This does not happen with normal video, it just happens here as
223 the motion of the chroma plane does not match the luma plane. */
224 c->mb_decision=2;
226 // some formats want stream headers to be separate
227 if(oc->oformat->flags & AVFMT_GLOBALHEADER)
228 c->flags |= CODEC_FLAG_GLOBAL_HEADER;
230 return st;
233 static AVFrame *alloc_picture(int pix_fmt, int width, int height)
235 AVFrame *picture;
236 uint8_t *picture_buf;
237 int size;
239 picture = avcodec_alloc_frame();
240 if (!picture)
241 return NULL;
242 size = avpicture_get_size(pix_fmt, width, height);
243 picture_buf = av_malloc(size);
244 if (!picture_buf) {
245 av_free(picture);
246 return NULL;
248 avpicture_fill((AVPicture *)picture, picture_buf,
249 pix_fmt, width, height);
250 return picture;
253 static void open_video(AVFormatContext *oc, AVStream *st)
255 AVCodec *codec;
256 AVCodecContext *c;
258 c = st->codec;
260 /* find the video encoder */
261 codec = avcodec_find_encoder(c->codec_id);
262 if (!codec) {
263 fprintf(stderr, "codec not found\n");
264 exit(1);
267 /* open the codec */
268 if (avcodec_open(c, codec) < 0) {
269 fprintf(stderr, "could not open codec\n");
270 exit(1);
273 video_outbuf = NULL;
274 if (!(oc->oformat->flags & AVFMT_RAWPICTURE)) {
275 /* allocate output buffer */
276 /* XXX: API change will be done */
277 /* buffers passed into lav* can be allocated any way you prefer,
278 as long as they're aligned enough for the architecture, and
279 they're freed appropriately (such as using av_free for buffers
280 allocated with av_malloc) */
281 video_outbuf_size = 200000;
282 video_outbuf = av_malloc(video_outbuf_size);
285 /* allocate the encoded raw picture */
286 picture = alloc_picture(c->pix_fmt, c->width, c->height);
287 if (!picture) {
288 fprintf(stderr, "Could not allocate picture\n");
289 exit(1);
292 /* if the output format is not YUV420P, then a temporary YUV420P
293 picture is needed too. It is then converted to the required
294 output format */
295 tmp_picture = NULL;
296 if (c->pix_fmt != PIX_FMT_YUV420P) {
297 tmp_picture = alloc_picture(PIX_FMT_YUV420P, c->width, c->height);
298 if (!tmp_picture) {
299 fprintf(stderr, "Could not allocate temporary picture\n");
300 exit(1);
305 /* prepare a dummy image */
306 static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
308 int x, y, i;
310 i = frame_index;
312 /* Y */
313 for(y=0;y<height;y++) {
314 for(x=0;x<width;x++) {
315 pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
319 /* Cb and Cr */
320 for(y=0;y<height/2;y++) {
321 for(x=0;x<width/2;x++) {
322 pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
323 pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
328 static void write_video_frame(AVFormatContext *oc, AVStream *st)
330 int out_size, ret;
331 AVCodecContext *c;
332 static struct SwsContext *img_convert_ctx;
334 c = st->codec;
336 if (frame_count >= STREAM_NB_FRAMES) {
337 /* no more frame to compress. The codec has a latency of a few
338 frames if using B frames, so we get the last frames by
339 passing the same picture again */
340 } else {
341 if (c->pix_fmt != PIX_FMT_YUV420P) {
342 /* as we only generate a YUV420P picture, we must convert it
343 to the codec pixel format if needed */
344 if (img_convert_ctx == NULL) {
345 img_convert_ctx = sws_getContext(c->width, c->height,
346 PIX_FMT_YUV420P,
347 c->width, c->height,
348 c->pix_fmt,
349 sws_flags, NULL, NULL, NULL);
350 if (img_convert_ctx == NULL) {
351 fprintf(stderr, "Cannot initialize the conversion context\n");
352 exit(1);
355 fill_yuv_image(tmp_picture, frame_count, c->width, c->height);
356 sws_scale(img_convert_ctx, tmp_picture->data, tmp_picture->linesize,
357 0, c->height, picture->data, picture->linesize);
358 } else {
359 fill_yuv_image(picture, frame_count, c->width, c->height);
364 if (oc->oformat->flags & AVFMT_RAWPICTURE) {
365 /* raw video case. The API will change slightly in the near
366 futur for that */
367 AVPacket pkt;
368 av_init_packet(&pkt);
370 pkt.flags |= PKT_FLAG_KEY;
371 pkt.stream_index= st->index;
372 pkt.data= (uint8_t *)picture;
373 pkt.size= sizeof(AVPicture);
375 ret = av_interleaved_write_frame(oc, &pkt);
376 } else {
377 /* encode the image */
378 out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture);
379 /* if zero size, it means the image was buffered */
380 if (out_size > 0) {
381 AVPacket pkt;
382 av_init_packet(&pkt);
384 if (c->coded_frame->pts != AV_NOPTS_VALUE)
385 pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base);
386 if(c->coded_frame->key_frame)
387 pkt.flags |= PKT_FLAG_KEY;
388 pkt.stream_index= st->index;
389 pkt.data= video_outbuf;
390 pkt.size= out_size;
392 /* write the compressed frame in the media file */
393 ret = av_interleaved_write_frame(oc, &pkt);
394 } else {
395 ret = 0;
398 if (ret != 0) {
399 fprintf(stderr, "Error while writing video frame\n");
400 exit(1);
402 frame_count++;
405 static void close_video(AVFormatContext *oc, AVStream *st)
407 avcodec_close(st->codec);
408 av_free(picture->data[0]);
409 av_free(picture);
410 if (tmp_picture) {
411 av_free(tmp_picture->data[0]);
412 av_free(tmp_picture);
414 av_free(video_outbuf);
417 /**************************************************************/
418 /* media file output */
420 int main(int argc, char **argv)
422 const char *filename;
423 AVOutputFormat *fmt;
424 AVFormatContext *oc;
425 AVStream *audio_st, *video_st;
426 double audio_pts, video_pts;
427 int i;
429 /* initialize libavcodec, and register all codecs and formats */
430 av_register_all();
432 if (argc != 2) {
433 printf("usage: %s output_file\n"
434 "API example program to output a media file with libavformat.\n"
435 "The output format is automatically guessed according to the file extension.\n"
436 "Raw images can also be output by using '%%d' in the filename\n"
437 "\n", argv[0]);
438 exit(1);
441 filename = argv[1];
443 /* auto detect the output format from the name. default is
444 mpeg. */
445 fmt = guess_format(NULL, filename, NULL);
446 if (!fmt) {
447 printf("Could not deduce output format from file extension: using MPEG.\n");
448 fmt = guess_format("mpeg", NULL, NULL);
450 if (!fmt) {
451 fprintf(stderr, "Could not find suitable output format\n");
452 exit(1);
455 /* allocate the output media context */
456 oc = avformat_alloc_context();
457 if (!oc) {
458 fprintf(stderr, "Memory error\n");
459 exit(1);
461 oc->oformat = fmt;
462 snprintf(oc->filename, sizeof(oc->filename), "%s", filename);
464 /* add the audio and video streams using the default format codecs
465 and initialize the codecs */
466 video_st = NULL;
467 audio_st = NULL;
468 if (fmt->video_codec != CODEC_ID_NONE) {
469 video_st = add_video_stream(oc, fmt->video_codec);
471 if (fmt->audio_codec != CODEC_ID_NONE) {
472 audio_st = add_audio_stream(oc, fmt->audio_codec);
475 /* set the output parameters (must be done even if no
476 parameters). */
477 if (av_set_parameters(oc, NULL) < 0) {
478 fprintf(stderr, "Invalid output format parameters\n");
479 exit(1);
482 dump_format(oc, 0, filename, 1);
484 /* now that all the parameters are set, we can open the audio and
485 video codecs and allocate the necessary encode buffers */
486 if (video_st)
487 open_video(oc, video_st);
488 if (audio_st)
489 open_audio(oc, audio_st);
491 /* open the output file, if needed */
492 if (!(fmt->flags & AVFMT_NOFILE)) {
493 if (url_fopen(&oc->pb, filename, URL_WRONLY) < 0) {
494 fprintf(stderr, "Could not open '%s'\n", filename);
495 exit(1);
499 /* write the stream header, if any */
500 av_write_header(oc);
502 for(;;) {
503 /* compute current audio and video time */
504 if (audio_st)
505 audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den;
506 else
507 audio_pts = 0.0;
509 if (video_st)
510 video_pts = (double)video_st->pts.val * video_st->time_base.num / video_st->time_base.den;
511 else
512 video_pts = 0.0;
514 if ((!audio_st || audio_pts >= STREAM_DURATION) &&
515 (!video_st || video_pts >= STREAM_DURATION))
516 break;
518 /* write interleaved audio and video frames */
519 if (!video_st || (video_st && audio_st && audio_pts < video_pts)) {
520 write_audio_frame(oc, audio_st);
521 } else {
522 write_video_frame(oc, video_st);
526 /* write the trailer, if any. the trailer must be written
527 * before you close the CodecContexts open when you wrote the
528 * header; otherwise write_trailer may try to use memory that
529 * was freed on av_codec_close() */
530 av_write_trailer(oc);
532 /* close each codec */
533 if (video_st)
534 close_video(oc, video_st);
535 if (audio_st)
536 close_audio(oc, audio_st);
538 /* free the streams */
539 for(i = 0; i < oc->nb_streams; i++) {
540 av_freep(&oc->streams[i]->codec);
541 av_freep(&oc->streams[i]);
544 if (!(fmt->flags & AVFMT_NOFILE)) {
545 /* close the output file */
546 url_fclose(oc->pb);
549 /* free the stream */
550 av_free(oc);
552 return 0;