1/* 2 * copyright (c) 2001 Fabrice Bellard 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21/** 22 * @file 23 * avcodec API use example. 24 * 25 * Note that this library only handles codecs (mpeg, mpeg4, etc...), 26 * not file formats (avi, vob, etc...). See library 'libavformat' for the 27 * format handling 28 */ 29 30#include <stdlib.h> 31#include <stdio.h> 32#include <string.h> 33 34#ifdef HAVE_AV_CONFIG_H 35#undef HAVE_AV_CONFIG_H 36#endif 37 38#include "libavcodec/avcodec.h" 39#include "libavutil/mathematics.h" 40 41#define INBUF_SIZE 4096 42#define AUDIO_INBUF_SIZE 20480 43#define AUDIO_REFILL_THRESH 4096 44 45/* 46 * Audio encoding example 47 */ 48static void audio_encode_example(const char *filename) 49{ 50 AVCodec *codec; 51 AVCodecContext *c= NULL; 52 int frame_size, i, j, out_size, outbuf_size; 53 FILE *f; 54 short *samples; 55 float t, tincr; 56 uint8_t *outbuf; 57 58 printf("Audio encoding\n"); 59 60 /* find the MP2 encoder */ 61 codec = avcodec_find_encoder(CODEC_ID_MP2); 62 if (!codec) { 63 fprintf(stderr, "codec not found\n"); 64 exit(1); 65 } 66 67 c= avcodec_alloc_context(); 68 69 /* put sample parameters */ 70 c->bit_rate = 64000; 71 c->sample_rate = 44100; 72 c->channels = 2; 73 74 /* open it */ 75 if (avcodec_open(c, codec) < 0) { 76 fprintf(stderr, "could not open codec\n"); 77 exit(1); 78 } 79 80 /* the codec gives us the frame size, in samples */ 81 frame_size = c->frame_size; 82 samples = malloc(frame_size * 2 * c->channels); 83 outbuf_size = 10000; 84 outbuf = malloc(outbuf_size); 85 86 f = fopen(filename, "wb"); 87 if (!f) { 88 fprintf(stderr, "could not open %s\n", filename); 89 exit(1); 90 } 91 92 /* encode a single tone sound */ 93 t = 0; 94 tincr = 2 * M_PI * 440.0 / c->sample_rate; 95 for(i=0;i<200;i++) { 96 for(j=0;j<frame_size;j++) { 97 samples[2*j] = (int)(sin(t) * 10000); 98 samples[2*j+1] = samples[2*j]; 99 t += tincr; 100 } 101 /* encode the samples */ 102 out_size = avcodec_encode_audio(c, outbuf, outbuf_size, samples); 103 fwrite(outbuf, 1, out_size, f); 104 } 105 fclose(f); 106 free(outbuf); 107 free(samples); 108 109 avcodec_close(c); 110 av_free(c); 111} 112 113/* 114 * Audio decoding. 115 */ 116static void audio_decode_example(const char *outfilename, const char *filename) 117{ 118 AVCodec *codec; 119 AVCodecContext *c= NULL; 120 int out_size, len; 121 FILE *f, *outfile; 122 uint8_t *outbuf; 123 uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE]; 124 AVPacket avpkt; 125 126 av_init_packet(&avpkt); 127 128 printf("Audio decoding\n"); 129 130 /* find the mpeg audio decoder */ 131 codec = avcodec_find_decoder(CODEC_ID_MP2); 132 if (!codec) { 133 fprintf(stderr, "codec not found\n"); 134 exit(1); 135 } 136 137 c= avcodec_alloc_context(); 138 139 /* open it */ 140 if (avcodec_open(c, codec) < 0) { 141 fprintf(stderr, "could not open codec\n"); 142 exit(1); 143 } 144 145 outbuf = malloc(AVCODEC_MAX_AUDIO_FRAME_SIZE); 146 147 f = fopen(filename, "rb"); 148 if (!f) { 149 fprintf(stderr, "could not open %s\n", filename); 150 exit(1); 151 } 152 outfile = fopen(outfilename, "wb"); 153 if (!outfile) { 154 av_free(c); 155 exit(1); 156 } 157 158 /* decode until eof */ 159 avpkt.data = inbuf; 160 avpkt.size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f); 161 162 while (avpkt.size > 0) { 163 out_size = AVCODEC_MAX_AUDIO_FRAME_SIZE; 164 len = avcodec_decode_audio3(c, (short *)outbuf, &out_size, &avpkt); 165 if (len < 0) { 166 fprintf(stderr, "Error while decoding\n"); 167 exit(1); 168 } 169 if (out_size > 0) { 170 /* if a frame has been decoded, output it */ 171 fwrite(outbuf, 1, out_size, outfile); 172 } 173 avpkt.size -= len; 174 avpkt.data += len; 175 if (avpkt.size < AUDIO_REFILL_THRESH) { 176 /* Refill the input buffer, to avoid trying to decode 177 * incomplete frames. Instead of this, one could also use 178 * a parser, or use a proper container format through 179 * libavformat. */ 180 memmove(inbuf, avpkt.data, avpkt.size); 181 avpkt.data = inbuf; 182 len = fread(avpkt.data + avpkt.size, 1, 183 AUDIO_INBUF_SIZE - avpkt.size, f); 184 if (len > 0) 185 avpkt.size += len; 186 } 187 } 188 189 fclose(outfile); 190 fclose(f); 191 free(outbuf); 192 193 avcodec_close(c); 194 av_free(c); 195} 196 197/* 198 * Video encoding example 199 */ 200static void video_encode_example(const char *filename) 201{ 202 AVCodec *codec; 203 AVCodecContext *c= NULL; 204 int i, out_size, size, x, y, outbuf_size; 205 FILE *f; 206 AVFrame *picture; 207 uint8_t *outbuf, *picture_buf; 208 209 printf("Video encoding\n"); 210 211 /* find the mpeg1 video encoder */ 212 codec = avcodec_find_encoder(CODEC_ID_MPEG1VIDEO); 213 if (!codec) { 214 fprintf(stderr, "codec not found\n"); 215 exit(1); 216 } 217 218 c= avcodec_alloc_context(); 219 picture= avcodec_alloc_frame(); 220 221 /* put sample parameters */ 222 c->bit_rate = 400000; 223 /* resolution must be a multiple of two */ 224 c->width = 352; 225 c->height = 288; 226 /* frames per second */ 227 c->time_base= (AVRational){1,25}; 228 c->gop_size = 10; /* emit one intra frame every ten frames */ 229 c->max_b_frames=1; 230 c->pix_fmt = PIX_FMT_YUV420P; 231 232 /* open it */ 233 if (avcodec_open(c, codec) < 0) { 234 fprintf(stderr, "could not open codec\n"); 235 exit(1); 236 } 237 238 f = fopen(filename, "wb"); 239 if (!f) { 240 fprintf(stderr, "could not open %s\n", filename); 241 exit(1); 242 } 243 244 /* alloc image and output buffer */ 245 outbuf_size = 100000; 246 outbuf = malloc(outbuf_size); 247 size = c->width * c->height; 248 picture_buf = malloc((size * 3) / 2); /* size for YUV 420 */ 249 250 picture->data[0] = picture_buf; 251 picture->data[1] = picture->data[0] + size; 252 picture->data[2] = picture->data[1] + size / 4; 253 picture->linesize[0] = c->width; 254 picture->linesize[1] = c->width / 2; 255 picture->linesize[2] = c->width / 2; 256 257 /* encode 1 second of video */ 258 for(i=0;i<25;i++) { 259 fflush(stdout); 260 /* prepare a dummy image */ 261 /* Y */ 262 for(y=0;y<c->height;y++) { 263 for(x=0;x<c->width;x++) { 264 picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3; 265 } 266 } 267 268 /* Cb and Cr */ 269 for(y=0;y<c->height/2;y++) { 270 for(x=0;x<c->width/2;x++) { 271 picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2; 272 picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5; 273 } 274 } 275 276 /* encode the image */ 277 out_size = avcodec_encode_video(c, outbuf, outbuf_size, picture); 278 printf("encoding frame %3d (size=%5d)\n", i, out_size); 279 fwrite(outbuf, 1, out_size, f); 280 } 281 282 /* get the delayed frames */ 283 for(; out_size; i++) { 284 fflush(stdout); 285 286 out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL); 287 printf("write frame %3d (size=%5d)\n", i, out_size); 288 fwrite(outbuf, 1, out_size, f); 289 } 290 291 /* add sequence end code to have a real mpeg file */ 292 outbuf[0] = 0x00; 293 outbuf[1] = 0x00; 294 outbuf[2] = 0x01; 295 outbuf[3] = 0xb7; 296 fwrite(outbuf, 1, 4, f); 297 fclose(f); 298 free(picture_buf); 299 free(outbuf); 300 301 avcodec_close(c); 302 av_free(c); 303 av_free(picture); 304 printf("\n"); 305} 306 307/* 308 * Video decoding example 309 */ 310 311static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize, 312 char *filename) 313{ 314 FILE *f; 315 int i; 316 317 f=fopen(filename,"w"); 318 fprintf(f,"P5\n%d %d\n%d\n",xsize,ysize,255); 319 for(i=0;i<ysize;i++) 320 fwrite(buf + i * wrap,1,xsize,f); 321 fclose(f); 322} 323 324static void video_decode_example(const char *outfilename, const char *filename) 325{ 326 AVCodec *codec; 327 AVCodecContext *c= NULL; 328 int frame, got_picture, len; 329 FILE *f; 330 AVFrame *picture; 331 uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE]; 332 char buf[1024]; 333 AVPacket avpkt; 334 335 av_init_packet(&avpkt); 336 337 /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */ 338 memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE); 339 340 printf("Video decoding\n"); 341 342 /* find the mpeg1 video decoder */ 343 codec = avcodec_find_decoder(CODEC_ID_MPEG1VIDEO); 344 if (!codec) { 345 fprintf(stderr, "codec not found\n"); 346 exit(1); 347 } 348 349 c= avcodec_alloc_context(); 350 picture= avcodec_alloc_frame(); 351 352 if(codec->capabilities&CODEC_CAP_TRUNCATED) 353 c->flags|= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */ 354 355 /* For some codecs, such as msmpeg4 and mpeg4, width and height 356 MUST be initialized there because this information is not 357 available in the bitstream. */ 358 359 /* open it */ 360 if (avcodec_open(c, codec) < 0) { 361 fprintf(stderr, "could not open codec\n"); 362 exit(1); 363 } 364 365 /* the codec gives us the frame size, in samples */ 366 367 f = fopen(filename, "rb"); 368 if (!f) { 369 fprintf(stderr, "could not open %s\n", filename); 370 exit(1); 371 } 372 373 frame = 0; 374 for(;;) { 375 avpkt.size = fread(inbuf, 1, INBUF_SIZE, f); 376 if (avpkt.size == 0) 377 break; 378 379 /* NOTE1: some codecs are stream based (mpegvideo, mpegaudio) 380 and this is the only method to use them because you cannot 381 know the compressed data size before analysing it. 382 383 BUT some other codecs (msmpeg4, mpeg4) are inherently frame 384 based, so you must call them with all the data for one 385 frame exactly. You must also initialize 'width' and 386 'height' before initializing them. */ 387 388 /* NOTE2: some codecs allow the raw parameters (frame size, 389 sample rate) to be changed at any frame. We handle this, so 390 you should also take care of it */ 391 392 /* here, we use a stream based decoder (mpeg1video), so we 393 feed decoder and see if it could decode a frame */ 394 avpkt.data = inbuf; 395 while (avpkt.size > 0) { 396 len = avcodec_decode_video2(c, picture, &got_picture, &avpkt); 397 if (len < 0) { 398 fprintf(stderr, "Error while decoding frame %d\n", frame); 399 exit(1); 400 } 401 if (got_picture) { 402 printf("saving frame %3d\n", frame); 403 fflush(stdout); 404 405 /* the picture is allocated by the decoder. no need to 406 free it */ 407 snprintf(buf, sizeof(buf), outfilename, frame); 408 pgm_save(picture->data[0], picture->linesize[0], 409 c->width, c->height, buf); 410 frame++; 411 } 412 avpkt.size -= len; 413 avpkt.data += len; 414 } 415 } 416 417 /* some codecs, such as MPEG, transmit the I and P frame with a 418 latency of one frame. You must do the following to have a 419 chance to get the last frame of the video */ 420 avpkt.data = NULL; 421 avpkt.size = 0; 422 len = avcodec_decode_video2(c, picture, &got_picture, &avpkt); 423 if (got_picture) { 424 printf("saving last frame %3d\n", frame); 425 fflush(stdout); 426 427 /* the picture is allocated by the decoder. no need to 428 free it */ 429 snprintf(buf, sizeof(buf), outfilename, frame); 430 pgm_save(picture->data[0], picture->linesize[0], 431 c->width, c->height, buf); 432 frame++; 433 } 434 435 fclose(f); 436 437 avcodec_close(c); 438 av_free(c); 439 av_free(picture); 440 printf("\n"); 441} 442 443int main(int argc, char **argv) 444{ 445 const char *filename; 446 447 /* must be called before using avcodec lib */ 448 avcodec_init(); 449 450 /* register all the codecs */ 451 avcodec_register_all(); 452 453 if (argc <= 1) { 454 audio_encode_example("/tmp/test.mp2"); 455 audio_decode_example("/tmp/test.sw", "/tmp/test.mp2"); 456 457 video_encode_example("/tmp/test.mpg"); 458 filename = "/tmp/test.mpg"; 459 } else { 460 filename = argv[1]; 461 } 462 463 // audio_decode_example("/tmp/test.sw", filename); 464 video_decode_example("/tmp/test%d.pgm", filename); 465 466 return 0; 467} 468