7a4a862c71ea6af5ffdac382190990daf706bc3d
[libav.git] / libavcodec / apiexample.c
1 /**
2 * @file apiexample.c
3 * avcodec API use example.
4 *
5 * Note that this library only handles codecs (mpeg, mpeg4, etc...),
6 * not file formats (avi, vob, etc...). See library 'libavformat' for the
7 * format handling
8 */
9
10 #include <stdlib.h>
11 #include <stdio.h>
12 #include <string.h>
13 #include <math.h>
14
15 #ifdef HAVE_AV_CONFIG_H
16 #undef HAVE_AV_CONFIG_H
17 #endif
18
19 #include "avcodec.h"
20
21 #define INBUF_SIZE 4096
22
23 /*
24 * Audio encoding example
25 */
26 void audio_encode_example(const char *filename)
27 {
28 AVCodec *codec;
29 AVCodecContext *c= NULL;
30 int frame_size, i, j, out_size, outbuf_size;
31 FILE *f;
32 short *samples;
33 float t, tincr;
34 uint8_t *outbuf;
35
36 printf("Audio encoding\n");
37
38 /* find the MP2 encoder */
39 codec = avcodec_find_encoder(CODEC_ID_MP2);
40 if (!codec) {
41 fprintf(stderr, "codec not found\n");
42 exit(1);
43 }
44
45 c= avcodec_alloc_context();
46
47 /* put sample parameters */
48 c->bit_rate = 64000;
49 c->sample_rate = 44100;
50 c->channels = 2;
51
52 /* open it */
53 if (avcodec_open(c, codec) < 0) {
54 fprintf(stderr, "could not open codec\n");
55 exit(1);
56 }
57
58 /* the codec gives us the frame size, in samples */
59 frame_size = c->frame_size;
60 samples = malloc(frame_size * 2 * c->channels);
61 outbuf_size = 10000;
62 outbuf = malloc(outbuf_size);
63
64 f = fopen(filename, "wb");
65 if (!f) {
66 fprintf(stderr, "could not open %s\n", filename);
67 exit(1);
68 }
69
70 /* encode a single tone sound */
71 t = 0;
72 tincr = 2 * M_PI * 440.0 / c->sample_rate;
73 for(i=0;i<200;i++) {
74 for(j=0;j<frame_size;j++) {
75 samples[2*j] = (int)(sin(t) * 10000);
76 samples[2*j+1] = samples[2*j];
77 t += tincr;
78 }
79 /* encode the samples */
80 out_size = avcodec_encode_audio(c, outbuf, outbuf_size, samples);
81 fwrite(outbuf, 1, out_size, f);
82 }
83 fclose(f);
84 free(outbuf);
85 free(samples);
86
87 avcodec_close(c);
88 av_free(c);
89 }
90
91 /*
92 * Audio decoding.
93 */
94 void audio_decode_example(const char *outfilename, const char *filename)
95 {
96 AVCodec *codec;
97 AVCodecContext *c= NULL;
98 int out_size, size, len;
99 FILE *f, *outfile;
100 uint8_t *outbuf;
101 uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE], *inbuf_ptr;
102
103 printf("Audio decoding\n");
104
105 /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */
106 memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE);
107
108 /* find the mpeg audio decoder */
109 codec = avcodec_find_decoder(CODEC_ID_MP2);
110 if (!codec) {
111 fprintf(stderr, "codec not found\n");
112 exit(1);
113 }
114
115 c= avcodec_alloc_context();
116
117 /* open it */
118 if (avcodec_open(c, codec) < 0) {
119 fprintf(stderr, "could not open codec\n");
120 exit(1);
121 }
122
123 outbuf = malloc(AVCODEC_MAX_AUDIO_FRAME_SIZE);
124
125 f = fopen(filename, "rb");
126 if (!f) {
127 fprintf(stderr, "could not open %s\n", filename);
128 exit(1);
129 }
130 outfile = fopen(outfilename, "wb");
131 if (!outfile) {
132 av_free(c);
133 exit(1);
134 }
135
136 /* decode until eof */
137 inbuf_ptr = inbuf;
138 for(;;) {
139 size = fread(inbuf, 1, INBUF_SIZE, f);
140 if (size == 0)
141 break;
142
143 inbuf_ptr = inbuf;
144 while (size > 0) {
145 len = avcodec_decode_audio(c, (short *)outbuf, &out_size,
146 inbuf_ptr, size);
147 if (len < 0) {
148 fprintf(stderr, "Error while decoding\n");
149 exit(1);
150 }
151 if (out_size > 0) {
152 /* if a frame has been decoded, output it */
153 fwrite(outbuf, 1, out_size, outfile);
154 }
155 size -= len;
156 inbuf_ptr += len;
157 }
158 }
159
160 fclose(outfile);
161 fclose(f);
162 free(outbuf);
163
164 avcodec_close(c);
165 av_free(c);
166 }
167
168 /*
169 * Video encoding example
170 */
171 void video_encode_example(const char *filename)
172 {
173 AVCodec *codec;
174 AVCodecContext *c= NULL;
175 int i, out_size, size, x, y, outbuf_size;
176 FILE *f;
177 AVFrame *picture;
178 uint8_t *outbuf, *picture_buf;
179
180 printf("Video encoding\n");
181
182 /* find the mpeg1 video encoder */
183 codec = avcodec_find_encoder(CODEC_ID_MPEG1VIDEO);
184 if (!codec) {
185 fprintf(stderr, "codec not found\n");
186 exit(1);
187 }
188
189 c= avcodec_alloc_context();
190 picture= avcodec_alloc_frame();
191
192 /* put sample parameters */
193 c->bit_rate = 400000;
194 /* resolution must be a multiple of two */
195 c->width = 352;
196 c->height = 288;
197 /* frames per second */
198 c->frame_rate = 25;
199 c->frame_rate_base= 1;
200 c->gop_size = 10; /* emit one intra frame every ten frames */
201 c->max_b_frames=1;
202
203 /* open it */
204 if (avcodec_open(c, codec) < 0) {
205 fprintf(stderr, "could not open codec\n");
206 exit(1);
207 }
208
209 /* the codec gives us the frame size, in samples */
210
211 f = fopen(filename, "wb");
212 if (!f) {
213 fprintf(stderr, "could not open %s\n", filename);
214 exit(1);
215 }
216
217 /* alloc image and output buffer */
218 outbuf_size = 100000;
219 outbuf = malloc(outbuf_size);
220 size = c->width * c->height;
221 picture_buf = malloc((size * 3) / 2); /* size for YUV 420 */
222
223 picture->data[0] = picture_buf;
224 picture->data[1] = picture->data[0] + size;
225 picture->data[2] = picture->data[1] + size / 4;
226 picture->linesize[0] = c->width;
227 picture->linesize[1] = c->width / 2;
228 picture->linesize[2] = c->width / 2;
229
230 /* encode 1 second of video */
231 for(i=0;i<25;i++) {
232 fflush(stdout);
233 /* prepare a dummy image */
234 /* Y */
235 for(y=0;y<c->height;y++) {
236 for(x=0;x<c->width;x++) {
237 picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3;
238 }
239 }
240
241 /* Cb and Cr */
242 for(y=0;y<c->height/2;y++) {
243 for(x=0;x<c->width/2;x++) {
244 picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2;
245 picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5;
246 }
247 }
248
249 /* encode the image */
250 out_size = avcodec_encode_video(c, outbuf, outbuf_size, picture);
251 printf("encoding frame %3d (size=%5d)\n", i, out_size);
252 fwrite(outbuf, 1, out_size, f);
253 }
254
255 /* get the delayed frames */
256 for(; out_size; i++) {
257 fflush(stdout);
258
259 out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL);
260 printf("write frame %3d (size=%5d)\n", i, out_size);
261 fwrite(outbuf, 1, out_size, f);
262 }
263
264 /* add sequence end code to have a real mpeg file */
265 outbuf[0] = 0x00;
266 outbuf[1] = 0x00;
267 outbuf[2] = 0x01;
268 outbuf[3] = 0xb7;
269 fwrite(outbuf, 1, 4, f);
270 fclose(f);
271 free(picture_buf);
272 free(outbuf);
273
274 avcodec_close(c);
275 av_free(c);
276 av_free(picture);
277 printf("\n");
278 }
279
280 /*
281 * Video decoding example
282 */
283
284 void pgm_save(unsigned char *buf,int wrap, int xsize,int ysize,char *filename)
285 {
286 FILE *f;
287 int i;
288
289 f=fopen(filename,"w");
290 fprintf(f,"P5\n%d %d\n%d\n",xsize,ysize,255);
291 for(i=0;i<ysize;i++)
292 fwrite(buf + i * wrap,1,xsize,f);
293 fclose(f);
294 }
295
296 void video_decode_example(const char *outfilename, const char *filename)
297 {
298 AVCodec *codec;
299 AVCodecContext *c= NULL;
300 int frame, size, got_picture, len;
301 FILE *f;
302 AVFrame *picture;
303 uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE], *inbuf_ptr;
304 char buf[1024];
305
306 /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */
307 memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE);
308
309 printf("Video decoding\n");
310
311 /* find the mpeg1 video decoder */
312 codec = avcodec_find_decoder(CODEC_ID_MPEG1VIDEO);
313 if (!codec) {
314 fprintf(stderr, "codec not found\n");
315 exit(1);
316 }
317
318 c= avcodec_alloc_context();
319 picture= avcodec_alloc_frame();
320
321 if(codec->capabilities&CODEC_CAP_TRUNCATED)
322 c->flags|= CODEC_FLAG_TRUNCATED; /* we dont send complete frames */
323
324 /* for some codecs, such as msmpeg4 and mpeg4, width and height
325 MUST be initialized there because these info are not available
326 in the bitstream */
327
328 /* open it */
329 if (avcodec_open(c, codec) < 0) {
330 fprintf(stderr, "could not open codec\n");
331 exit(1);
332 }
333
334 /* the codec gives us the frame size, in samples */
335
336 f = fopen(filename, "rb");
337 if (!f) {
338 fprintf(stderr, "could not open %s\n", filename);
339 exit(1);
340 }
341
342 frame = 0;
343 for(;;) {
344 size = fread(inbuf, 1, INBUF_SIZE, f);
345 if (size == 0)
346 break;
347
348 /* NOTE1: some codecs are stream based (mpegvideo, mpegaudio)
349 and this is the only method to use them because you cannot
350 know the compressed data size before analysing it.
351
352 BUT some other codecs (msmpeg4, mpeg4) are inherently frame
353 based, so you must call them with all the data for one
354 frame exactly. You must also initialize 'width' and
355 'height' before initializing them. */
356
357 /* NOTE2: some codecs allow the raw parameters (frame size,
358 sample rate) to be changed at any frame. We handle this, so
359 you should also take care of it */
360
361 /* here, we use a stream based decoder (mpeg1video), so we
362 feed decoder and see if it could decode a frame */
363 inbuf_ptr = inbuf;
364 while (size > 0) {
365 len = avcodec_decode_video(c, picture, &got_picture,
366 inbuf_ptr, size);
367 if (len < 0) {
368 fprintf(stderr, "Error while decoding frame %d\n", frame);
369 exit(1);
370 }
371 if (got_picture) {
372 printf("saving frame %3d\n", frame);
373 fflush(stdout);
374
375 /* the picture is allocated by the decoder. no need to
376 free it */
377 snprintf(buf, sizeof(buf), outfilename, frame);
378 pgm_save(picture->data[0], picture->linesize[0],
379 c->width, c->height, buf);
380 frame++;
381 }
382 size -= len;
383 inbuf_ptr += len;
384 }
385 }
386
387 /* some codecs, such as MPEG, transmit the I and P frame with a
388 latency of one frame. You must do the following to have a
389 chance to get the last frame of the video */
390 len = avcodec_decode_video(c, picture, &got_picture,
391 NULL, 0);
392 if (got_picture) {
393 printf("saving last frame %3d\n", frame);
394 fflush(stdout);
395
396 /* the picture is allocated by the decoder. no need to
397 free it */
398 snprintf(buf, sizeof(buf), outfilename, frame);
399 pgm_save(picture->data[0], picture->linesize[0],
400 c->width, c->height, buf);
401 frame++;
402 }
403
404 fclose(f);
405
406 avcodec_close(c);
407 av_free(c);
408 av_free(picture);
409 printf("\n");
410 }
411
412 // simple example how the options could be used
413 int options_example(int argc, char* argv[])
414 {
415 AVCodec* codec = avcodec_find_encoder_by_name((argc > 1) ? argv[2] : "mpeg4");
416 const AVOption* c;
417 AVCodecContext* avctx;
418 #define DEF_SIZE 5000
419 char* def = av_malloc(DEF_SIZE);
420 const char* col = "";
421 int i = 0;
422
423 if (!codec)
424 return -1;
425 c = codec->options;
426 avctx = avcodec_alloc_context();
427 *def = 0;
428
429 if (c) {
430 const AVOption *stack[FF_OPT_MAX_DEPTH];
431 int depth = 0;
432 for (;;) {
433 if (!c->name) {
434 if (c->help) {
435 stack[depth++] = c;
436 c = (const AVOption*)c->help;
437 } else {
438 if (depth == 0)
439 break; // finished
440 c = stack[--depth];
441 c++;
442 }
443 } else {
444 int t = c->type & FF_OPT_TYPE_MASK;
445 printf("Config %s %s\n",
446 t == FF_OPT_TYPE_BOOL ? "bool " :
447 t == FF_OPT_TYPE_DOUBLE ? "double " :
448 t == FF_OPT_TYPE_INT ? "integer" :
449 t == FF_OPT_TYPE_STRING ? "string " :
450 "unknown??", c->name);
451 switch (t) {
452 case FF_OPT_TYPE_BOOL:
453 i += snprintf(def + i, DEF_SIZE-i, "%s%s=%s",
454 col, c->name,
455 c->defval != 0. ? "on" : "off");
456 break;
457 case FF_OPT_TYPE_DOUBLE:
458 i += snprintf(def + i, DEF_SIZE-i, "%s%s=%f",
459 col, c->name, c->defval);
460 break;
461 case FF_OPT_TYPE_INT:
462 i += snprintf(def + i, DEF_SIZE-i, "%s%s=%d",
463 col, c->name, (int) c->defval);
464 break;
465 case FF_OPT_TYPE_STRING:
466 if (c->defstr) {
467 char* d = av_strdup(c->defstr);
468 char* f = strchr(d, ',');
469 if (f)
470 *f = 0;
471 i += snprintf(def + i, DEF_SIZE-i, "%s%s=%s",
472 col, c->name, d);
473 av_free(d);
474 }
475 break;
476 }
477 col = ":";
478 c++;
479 }
480 }
481 }
482 printf("Default Options: %s\n", def);
483 av_free(def);
484 return 0;
485 }
486
487
488 int main(int argc, char **argv)
489 {
490 const char *filename;
491
492 /* must be called before using avcodec lib */
493 avcodec_init();
494
495 /* register all the codecs (you can also register only the codec
496 you wish to have smaller code */
497 avcodec_register_all();
498
499 #ifdef OPT_TEST
500 options_example(argc, argv);
501 #else
502 if (argc <= 1) {
503 audio_encode_example("/tmp/test.mp2");
504 audio_decode_example("/tmp/test.sw", "/tmp/test.mp2");
505
506 video_encode_example("/tmp/test.mpg");
507 filename = "/tmp/test.mpg";
508 } else {
509 filename = argv[1];
510 }
511
512 // audio_decode_example("/tmp/test.sw", filename);
513 video_decode_example("/tmp/test%d.pgm", filename);
514 #endif
515
516 return 0;
517 }