VirtualBox

source: vbox/trunk/src/libs/ffmpeg-20060710/output_example.c@ 8998

最後變更 在這個檔案從8998是 5776,由 vboxsync 提交於 17 年 前

ffmpeg: exported to OSE

檔案大小: 15.0 KB
 
1/*
2 * Libavformat API example: Output a media file in any supported
3 * libavformat format. The default codecs are used.
4 *
5 * Copyright (c) 2003 Fabrice Bellard
6 *
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:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
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.
24 */
25#include <stdlib.h>
26#include <stdio.h>
27#include <string.h>
28#include <math.h>
29
30#ifndef M_PI
31#define M_PI 3.1415926535897931
32#endif
33
34#include "avformat.h"
35
36/* 5 seconds stream duration */
37#define STREAM_DURATION 5.0
38#define STREAM_FRAME_RATE 25 /* 25 images/s */
39#define STREAM_NB_FRAMES ((int)(STREAM_DURATION * STREAM_FRAME_RATE))
40#define STREAM_PIX_FMT PIX_FMT_YUV420P /* default pix_fmt */
41
42/**************************************************************/
43/* audio output */
44
45float t, tincr, tincr2;
46int16_t *samples;
47uint8_t *audio_outbuf;
48int audio_outbuf_size;
49int audio_input_frame_size;
50
51/*
52 * add an audio output stream
53 */
54static AVStream *add_audio_stream(AVFormatContext *oc, int codec_id)
55{
56 AVCodecContext *c;
57 AVStream *st;
58
59 st = av_new_stream(oc, 1);
60 if (!st) {
61 fprintf(stderr, "Could not alloc stream\n");
62 exit(1);
63 }
64
65 c = st->codec;
66 c->codec_id = codec_id;
67 c->codec_type = CODEC_TYPE_AUDIO;
68
69 /* put sample parameters */
70 c->bit_rate = 64000;
71 c->sample_rate = 44100;
72 c->channels = 2;
73 return st;
74}
75
76static void open_audio(AVFormatContext *oc, AVStream *st)
77{
78 AVCodecContext *c;
79 AVCodec *codec;
80
81 c = st->codec;
82
83 /* find the audio encoder */
84 codec = avcodec_find_encoder(c->codec_id);
85 if (!codec) {
86 fprintf(stderr, "codec not found\n");
87 exit(1);
88 }
89
90 /* open it */
91 if (avcodec_open(c, codec) < 0) {
92 fprintf(stderr, "could not open codec\n");
93 exit(1);
94 }
95
96 /* init signal generator */
97 t = 0;
98 tincr = 2 * M_PI * 110.0 / c->sample_rate;
99 /* increment frequency by 110 Hz per second */
100 tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
101
102 audio_outbuf_size = 10000;
103 audio_outbuf = malloc(audio_outbuf_size);
104
105 /* ugly hack for PCM codecs (will be removed ASAP with new PCM
106 support to compute the input frame size in samples */
107 if (c->frame_size <= 1) {
108 audio_input_frame_size = audio_outbuf_size / c->channels;
109 switch(st->codec->codec_id) {
110 case CODEC_ID_PCM_S16LE:
111 case CODEC_ID_PCM_S16BE:
112 case CODEC_ID_PCM_U16LE:
113 case CODEC_ID_PCM_U16BE:
114 audio_input_frame_size >>= 1;
115 break;
116 default:
117 break;
118 }
119 } else {
120 audio_input_frame_size = c->frame_size;
121 }
122 samples = malloc(audio_input_frame_size * 2 * c->channels);
123}
124
125/* prepare a 16 bit dummy audio frame of 'frame_size' samples and
126 'nb_channels' channels */
127static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels)
128{
129 int j, i, v;
130 int16_t *q;
131
132 q = samples;
133 for(j=0;j<frame_size;j++) {
134 v = (int)(sin(t) * 10000);
135 for(i = 0; i < nb_channels; i++)
136 *q++ = v;
137 t += tincr;
138 tincr += tincr2;
139 }
140}
141
142static void write_audio_frame(AVFormatContext *oc, AVStream *st)
143{
144 AVCodecContext *c;
145 AVPacket pkt;
146 av_init_packet(&pkt);
147
148 c = st->codec;
149
150 get_audio_frame(samples, audio_input_frame_size, c->channels);
151
152 pkt.size= avcodec_encode_audio(c, audio_outbuf, audio_outbuf_size, samples);
153
154 pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base);
155 pkt.flags |= PKT_FLAG_KEY;
156 pkt.stream_index= st->index;
157 pkt.data= audio_outbuf;
158
159 /* write the compressed frame in the media file */
160 if (av_write_frame(oc, &pkt) != 0) {
161 fprintf(stderr, "Error while writing audio frame\n");
162 exit(1);
163 }
164}
165
166static void close_audio(AVFormatContext *oc, AVStream *st)
167{
168 avcodec_close(st->codec);
169
170 av_free(samples);
171 av_free(audio_outbuf);
172}
173
174/**************************************************************/
175/* video output */
176
177AVFrame *picture, *tmp_picture;
178uint8_t *video_outbuf;
179int frame_count, video_outbuf_size;
180
181/* add a video output stream */
182static AVStream *add_video_stream(AVFormatContext *oc, int codec_id)
183{
184 AVCodecContext *c;
185 AVStream *st;
186
187 st = av_new_stream(oc, 0);
188 if (!st) {
189 fprintf(stderr, "Could not alloc stream\n");
190 exit(1);
191 }
192
193 c = st->codec;
194 c->codec_id = codec_id;
195 c->codec_type = CODEC_TYPE_VIDEO;
196
197 /* put sample parameters */
198 c->bit_rate = 400000;
199 /* resolution must be a multiple of two */
200 c->width = 352;
201 c->height = 288;
202 /* time base: this is the fundamental unit of time (in seconds) in terms
203 of which frame timestamps are represented. for fixed-fps content,
204 timebase should be 1/framerate and timestamp increments should be
205 identically 1. */
206 c->time_base.den = STREAM_FRAME_RATE;
207 c->time_base.num = 1;
208 c->gop_size = 12; /* emit one intra frame every twelve frames at most */
209 c->pix_fmt = STREAM_PIX_FMT;
210 if (c->codec_id == CODEC_ID_MPEG2VIDEO) {
211 /* just for testing, we also add B frames */
212 c->max_b_frames = 2;
213 }
214 if (c->codec_id == CODEC_ID_MPEG1VIDEO){
215 /* needed to avoid using macroblocks in which some coeffs overflow
216 this doesnt happen with normal video, it just happens here as the
217 motion of the chroma plane doesnt match the luma plane */
218 c->mb_decision=2;
219 }
220 // some formats want stream headers to be seperate
221 if(!strcmp(oc->oformat->name, "mp4") || !strcmp(oc->oformat->name, "mov") || !strcmp(oc->oformat->name, "3gp"))
222 c->flags |= CODEC_FLAG_GLOBAL_HEADER;
223
224 return st;
225}
226
227static AVFrame *alloc_picture(int pix_fmt, int width, int height)
228{
229 AVFrame *picture;
230 uint8_t *picture_buf;
231 int size;
232
233 picture = avcodec_alloc_frame();
234 if (!picture)
235 return NULL;
236 size = avpicture_get_size(pix_fmt, width, height);
237 picture_buf = malloc(size);
238 if (!picture_buf) {
239 av_free(picture);
240 return NULL;
241 }
242 avpicture_fill((AVPicture *)picture, picture_buf,
243 pix_fmt, width, height);
244 return picture;
245}
246
247static void open_video(AVFormatContext *oc, AVStream *st)
248{
249 AVCodec *codec;
250 AVCodecContext *c;
251
252 c = st->codec;
253
254 /* find the video encoder */
255 codec = avcodec_find_encoder(c->codec_id);
256 if (!codec) {
257 fprintf(stderr, "codec not found\n");
258 exit(1);
259 }
260
261 /* open the codec */
262 if (avcodec_open(c, codec) < 0) {
263 fprintf(stderr, "could not open codec\n");
264 exit(1);
265 }
266
267 video_outbuf = NULL;
268 if (!(oc->oformat->flags & AVFMT_RAWPICTURE)) {
269 /* allocate output buffer */
270 /* XXX: API change will be done */
271 video_outbuf_size = 200000;
272 video_outbuf = malloc(video_outbuf_size);
273 }
274
275 /* allocate the encoded raw picture */
276 picture = alloc_picture(c->pix_fmt, c->width, c->height);
277 if (!picture) {
278 fprintf(stderr, "Could not allocate picture\n");
279 exit(1);
280 }
281
282 /* if the output format is not YUV420P, then a temporary YUV420P
283 picture is needed too. It is then converted to the required
284 output format */
285 tmp_picture = NULL;
286 if (c->pix_fmt != PIX_FMT_YUV420P) {
287 tmp_picture = alloc_picture(PIX_FMT_YUV420P, c->width, c->height);
288 if (!tmp_picture) {
289 fprintf(stderr, "Could not allocate temporary picture\n");
290 exit(1);
291 }
292 }
293}
294
295/* prepare a dummy image */
296static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
297{
298 int x, y, i;
299
300 i = frame_index;
301
302 /* Y */
303 for(y=0;y<height;y++) {
304 for(x=0;x<width;x++) {
305 pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
306 }
307 }
308
309 /* Cb and Cr */
310 for(y=0;y<height/2;y++) {
311 for(x=0;x<width/2;x++) {
312 pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
313 pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
314 }
315 }
316}
317
318static void write_video_frame(AVFormatContext *oc, AVStream *st)
319{
320 int out_size, ret;
321 AVCodecContext *c;
322
323 c = st->codec;
324
325 if (frame_count >= STREAM_NB_FRAMES) {
326 /* no more frame to compress. The codec has a latency of a few
327 frames if using B frames, so we get the last frames by
328 passing the same picture again */
329 } else {
330 if (c->pix_fmt != PIX_FMT_YUV420P) {
331 /* as we only generate a YUV420P picture, we must convert it
332 to the codec pixel format if needed */
333 fill_yuv_image(tmp_picture, frame_count, c->width, c->height);
334 img_convert((AVPicture *)picture, c->pix_fmt,
335 (AVPicture *)tmp_picture, PIX_FMT_YUV420P,
336 c->width, c->height);
337 } else {
338 fill_yuv_image(picture, frame_count, c->width, c->height);
339 }
340 }
341
342
343 if (oc->oformat->flags & AVFMT_RAWPICTURE) {
344 /* raw video case. The API will change slightly in the near
345 futur for that */
346 AVPacket pkt;
347 av_init_packet(&pkt);
348
349 pkt.flags |= PKT_FLAG_KEY;
350 pkt.stream_index= st->index;
351 pkt.data= (uint8_t *)picture;
352 pkt.size= sizeof(AVPicture);
353
354 ret = av_write_frame(oc, &pkt);
355 } else {
356 /* encode the image */
357 out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture);
358 /* if zero size, it means the image was buffered */
359 if (out_size > 0) {
360 AVPacket pkt;
361 av_init_packet(&pkt);
362
363 pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base);
364 if(c->coded_frame->key_frame)
365 pkt.flags |= PKT_FLAG_KEY;
366 pkt.stream_index= st->index;
367 pkt.data= video_outbuf;
368 pkt.size= out_size;
369
370 /* write the compressed frame in the media file */
371 ret = av_write_frame(oc, &pkt);
372 } else {
373 ret = 0;
374 }
375 }
376 if (ret != 0) {
377 fprintf(stderr, "Error while writing video frame\n");
378 exit(1);
379 }
380 frame_count++;
381}
382
383static void close_video(AVFormatContext *oc, AVStream *st)
384{
385 avcodec_close(st->codec);
386 av_free(picture->data[0]);
387 av_free(picture);
388 if (tmp_picture) {
389 av_free(tmp_picture->data[0]);
390 av_free(tmp_picture);
391 }
392 av_free(video_outbuf);
393}
394
395/**************************************************************/
396/* media file output */
397
398int main(int argc, char **argv)
399{
400 const char *filename;
401 AVOutputFormat *fmt;
402 AVFormatContext *oc;
403 AVStream *audio_st, *video_st;
404 double audio_pts, video_pts;
405 int i;
406
407 /* initialize libavcodec, and register all codecs and formats */
408 av_register_all();
409
410 if (argc != 2) {
411 printf("usage: %s output_file\n"
412 "API example program to output a media file with libavformat.\n"
413 "The output format is automatically guessed according to the file extension.\n"
414 "Raw images can also be output by using '%%d' in the filename\n"
415 "\n", argv[0]);
416 exit(1);
417 }
418
419 filename = argv[1];
420
421 /* auto detect the output format from the name. default is
422 mpeg. */
423 fmt = guess_format(NULL, filename, NULL);
424 if (!fmt) {
425 printf("Could not deduce output format from file extension: using MPEG.\n");
426 fmt = guess_format("mpeg", NULL, NULL);
427 }
428 if (!fmt) {
429 fprintf(stderr, "Could not find suitable output format\n");
430 exit(1);
431 }
432
433 /* allocate the output media context */
434 oc = av_alloc_format_context();
435 if (!oc) {
436 fprintf(stderr, "Memory error\n");
437 exit(1);
438 }
439 oc->oformat = fmt;
440 snprintf(oc->filename, sizeof(oc->filename), "%s", filename);
441
442 /* add the audio and video streams using the default format codecs
443 and initialize the codecs */
444 video_st = NULL;
445 audio_st = NULL;
446 if (fmt->video_codec != CODEC_ID_NONE) {
447 video_st = add_video_stream(oc, fmt->video_codec);
448 }
449 if (fmt->audio_codec != CODEC_ID_NONE) {
450 audio_st = add_audio_stream(oc, fmt->audio_codec);
451 }
452
453 /* set the output parameters (must be done even if no
454 parameters). */
455 if (av_set_parameters(oc, NULL) < 0) {
456 fprintf(stderr, "Invalid output format parameters\n");
457 exit(1);
458 }
459
460 dump_format(oc, 0, filename, 1);
461
462 /* now that all the parameters are set, we can open the audio and
463 video codecs and allocate the necessary encode buffers */
464 if (video_st)
465 open_video(oc, video_st);
466 if (audio_st)
467 open_audio(oc, audio_st);
468
469 /* open the output file, if needed */
470 if (!(fmt->flags & AVFMT_NOFILE)) {
471 if (url_fopen(&oc->pb, filename, URL_WRONLY) < 0) {
472 fprintf(stderr, "Could not open '%s'\n", filename);
473 exit(1);
474 }
475 }
476
477 /* write the stream header, if any */
478 av_write_header(oc);
479
480 for(;;) {
481 /* compute current audio and video time */
482 if (audio_st)
483 audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den;
484 else
485 audio_pts = 0.0;
486
487 if (video_st)
488 video_pts = (double)video_st->pts.val * video_st->time_base.num / video_st->time_base.den;
489 else
490 video_pts = 0.0;
491
492 if ((!audio_st || audio_pts >= STREAM_DURATION) &&
493 (!video_st || video_pts >= STREAM_DURATION))
494 break;
495
496 /* write interleaved audio and video frames */
497 if (!video_st || (video_st && audio_st && audio_pts < video_pts)) {
498 write_audio_frame(oc, audio_st);
499 } else {
500 write_video_frame(oc, video_st);
501 }
502 }
503
504 /* close each codec */
505 if (video_st)
506 close_video(oc, video_st);
507 if (audio_st)
508 close_audio(oc, audio_st);
509
510 /* write the trailer, if any */
511 av_write_trailer(oc);
512
513 /* free the streams */
514 for(i = 0; i < oc->nb_streams; i++) {
515 av_freep(&oc->streams[i]->codec);
516 av_freep(&oc->streams[i]);
517 }
518
519 if (!(fmt->flags & AVFMT_NOFILE)) {
520 /* close the output file */
521 url_fclose(&oc->pb);
522 }
523
524 /* free the stream */
525 av_free(oc);
526
527 return 0;
528}
注意: 瀏覽 TracBrowser 來幫助您使用儲存庫瀏覽器

© 2024 Oracle Support Privacy / Do Not Sell My Info Terms of Use Trademark Policy Automated Access Etiquette