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| 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 libavcodec/apiexample.c | |
| 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 "avcodec.h" | |
| 39 | +#include "libavutil/mathematics.h" | |
| 40 | + | |
| 41 | +#define INBUF_SIZE 4096 | |
| 42 | + | |
| 43 | +/* | |
| 44 | + * Audio encoding example | |
| 45 | + */ | |
| 46 | +void audio_encode_example(const char *filename) | |
| 47 | +{ | |
| 48 | + AVCodec *codec; | |
| 49 | + AVCodecContext *c= NULL; | |
| 50 | + int frame_size, i, j, out_size, outbuf_size; | |
| 51 | + FILE *f; | |
| 52 | + short *samples; | |
| 53 | + float t, tincr; | |
| 54 | + uint8_t *outbuf; | |
| 55 | + | |
| 56 | + printf("Audio encoding\n"); | |
| 57 | + | |
| 58 | + /* find the MP2 encoder */ | |
| 59 | + codec = avcodec_find_encoder(CODEC_ID_MP2); | |
| 60 | + if (!codec) { | |
| 61 | + fprintf(stderr, "codec not found\n"); | |
| 62 | + exit(1); | |
| 63 | + } | |
| 64 | + | |
| 65 | + c= avcodec_alloc_context(); | |
| 66 | + | |
| 67 | + /* put sample parameters */ | |
| 68 | + c->bit_rate = 64000; | |
| 69 | + c->sample_rate = 44100; | |
| 70 | + c->channels = 2; | |
| 71 | + | |
| 72 | + /* open it */ | |
| 73 | + if (avcodec_open(c, codec) < 0) { | |
| 74 | + fprintf(stderr, "could not open codec\n"); | |
| 75 | + exit(1); | |
| 76 | + } | |
| 77 | + | |
| 78 | + /* the codec gives us the frame size, in samples */ | |
| 79 | + frame_size = c->frame_size; | |
| 80 | + samples = malloc(frame_size * 2 * c->channels); | |
| 81 | + outbuf_size = 10000; | |
| 82 | + outbuf = malloc(outbuf_size); | |
| 83 | + | |
| 84 | + f = fopen(filename, "wb"); | |
| 85 | + if (!f) { | |
| 86 | + fprintf(stderr, "could not open %s\n", filename); | |
| 87 | + exit(1); | |
| 88 | + } | |
| 89 | + | |
| 90 | + /* encode a single tone sound */ | |
| 91 | + t = 0; | |
| 92 | + tincr = 2 * M_PI * 440.0 / c->sample_rate; | |
| 93 | + for(i=0;i<200;i++) { | |
| 94 | + for(j=0;j<frame_size;j++) { | |
| 95 | + samples[2*j] = (int)(sin(t) * 10000); | |
| 96 | + samples[2*j+1] = samples[2*j]; | |
| 97 | + t += tincr; | |
| 98 | + } | |
| 99 | + /* encode the samples */ | |
| 100 | + out_size = avcodec_encode_audio(c, outbuf, outbuf_size, samples); | |
| 101 | + fwrite(outbuf, 1, out_size, f); | |
| 102 | + } | |
| 103 | + fclose(f); | |
| 104 | + free(outbuf); | |
| 105 | + free(samples); | |
| 106 | + | |
| 107 | + avcodec_close(c); | |
| 108 | + av_free(c); | |
| 109 | +} | |
| 110 | + | |
| 111 | +/* | |
| 112 | + * Audio decoding. | |
| 113 | + */ | |
| 114 | +void audio_decode_example(const char *outfilename, const char *filename) | |
| 115 | +{ | |
| 116 | + AVCodec *codec; | |
| 117 | + AVCodecContext *c= NULL; | |
| 118 | + int out_size, size, len; | |
| 119 | + FILE *f, *outfile; | |
| 120 | + uint8_t *outbuf; | |
| 121 | + uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE], *inbuf_ptr; | |
| 122 | + | |
| 123 | + printf("Audio decoding\n"); | |
| 124 | + | |
| 125 | + /* find the mpeg audio decoder */ | |
| 126 | + codec = avcodec_find_decoder(CODEC_ID_MP2); | |
| 127 | + if (!codec) { | |
| 128 | + fprintf(stderr, "codec not found\n"); | |
| 129 | + exit(1); | |
| 130 | + } | |
| 131 | + | |
| 132 | + c= avcodec_alloc_context(); | |
| 133 | + | |
| 134 | + /* open it */ | |
| 135 | + if (avcodec_open(c, codec) < 0) { | |
| 136 | + fprintf(stderr, "could not open codec\n"); | |
| 137 | + exit(1); | |
| 138 | + } | |
| 139 | + | |
| 140 | + outbuf = malloc(AVCODEC_MAX_AUDIO_FRAME_SIZE); | |
| 141 | + | |
| 142 | + f = fopen(filename, "rb"); | |
| 143 | + if (!f) { | |
| 144 | + fprintf(stderr, "could not open %s\n", filename); | |
| 145 | + exit(1); | |
| 146 | + } | |
| 147 | + outfile = fopen(outfilename, "wb"); | |
| 148 | + if (!outfile) { | |
| 149 | + av_free(c); | |
| 150 | + exit(1); | |
| 151 | + } | |
| 152 | + | |
| 153 | + /* decode until eof */ | |
| 154 | + inbuf_ptr = inbuf; | |
| 155 | + for(;;) { | |
| 156 | + size = fread(inbuf, 1, INBUF_SIZE, f); | |
| 157 | + if (size == 0) | |
| 158 | + break; | |
| 159 | + | |
| 160 | + inbuf_ptr = inbuf; | |
| 161 | + while (size > 0) { | |
| 162 | + out_size = AVCODEC_MAX_AUDIO_FRAME_SIZE; | |
| 163 | + len = avcodec_decode_audio2(c, (short *)outbuf, &out_size, | |
| 164 | + inbuf_ptr, size); | |
| 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 | + size -= len; | |
| 174 | + inbuf_ptr += len; | |
| 175 | + } | |
| 176 | + } | |
| 177 | + | |
| 178 | + fclose(outfile); | |
| 179 | + fclose(f); | |
| 180 | + free(outbuf); | |
| 181 | + | |
| 182 | + avcodec_close(c); | |
| 183 | + av_free(c); | |
| 184 | +} | |
| 185 | + | |
| 186 | +/* | |
| 187 | + * Video encoding example | |
| 188 | + */ | |
| 189 | +void video_encode_example(const char *filename) | |
| 190 | +{ | |
| 191 | + AVCodec *codec; | |
| 192 | + AVCodecContext *c= NULL; | |
| 193 | + int i, out_size, size, x, y, outbuf_size; | |
| 194 | + FILE *f; | |
| 195 | + AVFrame *picture; | |
| 196 | + uint8_t *outbuf, *picture_buf; | |
| 197 | + | |
| 198 | + printf("Video encoding\n"); | |
| 199 | + | |
| 200 | + /* find the mpeg1 video encoder */ | |
| 201 | + codec = avcodec_find_encoder(CODEC_ID_MPEG1VIDEO); | |
| 202 | + if (!codec) { | |
| 203 | + fprintf(stderr, "codec not found\n"); | |
| 204 | + exit(1); | |
| 205 | + } | |
| 206 | + | |
| 207 | + c= avcodec_alloc_context(); | |
| 208 | + picture= avcodec_alloc_frame(); | |
| 209 | + | |
| 210 | + /* put sample parameters */ | |
| 211 | + c->bit_rate = 400000; | |
| 212 | + /* resolution must be a multiple of two */ | |
| 213 | + c->width = 352; | |
| 214 | + c->height = 288; | |
| 215 | + /* frames per second */ | |
| 216 | + c->time_base= (AVRational){1,25}; | |
| 217 | + c->gop_size = 10; /* emit one intra frame every ten frames */ | |
| 218 | + c->max_b_frames=1; | |
| 219 | + c->pix_fmt = PIX_FMT_YUV420P; | |
| 220 | + | |
| 221 | + /* open it */ | |
| 222 | + if (avcodec_open(c, codec) < 0) { | |
| 223 | + fprintf(stderr, "could not open codec\n"); | |
| 224 | + exit(1); | |
| 225 | + } | |
| 226 | + | |
| 227 | + f = fopen(filename, "wb"); | |
| 228 | + if (!f) { | |
| 229 | + fprintf(stderr, "could not open %s\n", filename); | |
| 230 | + exit(1); | |
| 231 | + } | |
| 232 | + | |
| 233 | + /* alloc image and output buffer */ | |
| 234 | + outbuf_size = 100000; | |
| 235 | + outbuf = malloc(outbuf_size); | |
| 236 | + size = c->width * c->height; | |
| 237 | + picture_buf = malloc((size * 3) / 2); /* size for YUV 420 */ | |
| 238 | + | |
| 239 | + picture->data[0] = picture_buf; | |
| 240 | + picture->data[1] = picture->data[0] + size; | |
| 241 | + picture->data[2] = picture->data[1] + size / 4; | |
| 242 | + picture->linesize[0] = c->width; | |
| 243 | + picture->linesize[1] = c->width / 2; | |
| 244 | + picture->linesize[2] = c->width / 2; | |
| 245 | + | |
| 246 | + /* encode 1 second of video */ | |
| 247 | + for(i=0;i<25;i++) { | |
| 248 | + fflush(stdout); | |
| 249 | + /* prepare a dummy image */ | |
| 250 | + /* Y */ | |
| 251 | + for(y=0;y<c->height;y++) { | |
| 252 | + for(x=0;x<c->width;x++) { | |
| 253 | + picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3; | |
| 254 | + } | |
| 255 | + } | |
| 256 | + | |
| 257 | + /* Cb and Cr */ | |
| 258 | + for(y=0;y<c->height/2;y++) { | |
| 259 | + for(x=0;x<c->width/2;x++) { | |
| 260 | + picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2; | |
| 261 | + picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5; | |
| 262 | + } | |
| 263 | + } | |
| 264 | + | |
| 265 | + /* encode the image */ | |
| 266 | + out_size = avcodec_encode_video(c, outbuf, outbuf_size, picture); | |
| 267 | + printf("encoding frame %3d (size=%5d)\n", i, out_size); | |
| 268 | + fwrite(outbuf, 1, out_size, f); | |
| 269 | + } | |
| 270 | + | |
| 271 | + /* get the delayed frames */ | |
| 272 | + for(; out_size; i++) { | |
| 273 | + fflush(stdout); | |
| 274 | + | |
| 275 | + out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL); | |
| 276 | + printf("write frame %3d (size=%5d)\n", i, out_size); | |
| 277 | + fwrite(outbuf, 1, out_size, f); | |
| 278 | + } | |
| 279 | + | |
| 280 | + /* add sequence end code to have a real mpeg file */ | |
| 281 | + outbuf[0] = 0x00; | |
| 282 | + outbuf[1] = 0x00; | |
| 283 | + outbuf[2] = 0x01; | |
| 284 | + outbuf[3] = 0xb7; | |
| 285 | + fwrite(outbuf, 1, 4, f); | |
| 286 | + fclose(f); | |
| 287 | + free(picture_buf); | |
| 288 | + free(outbuf); | |
| 289 | + | |
| 290 | + avcodec_close(c); | |
| 291 | + av_free(c); | |
| 292 | + av_free(picture); | |
| 293 | + printf("\n"); | |
| 294 | +} | |
| 295 | + | |
| 296 | +/* | |
| 297 | + * Video decoding example | |
| 298 | + */ | |
| 299 | + | |
| 300 | +void pgm_save(unsigned char *buf,int wrap, int xsize,int ysize,char *filename) | |
| 301 | +{ | |
| 302 | + FILE *f; | |
| 303 | + int i; | |
| 304 | + | |
| 305 | + f=fopen(filename,"w"); | |
| 306 | + fprintf(f,"P5\n%d %d\n%d\n",xsize,ysize,255); | |
| 307 | + for(i=0;i<ysize;i++) | |
| 308 | + fwrite(buf + i * wrap,1,xsize,f); | |
| 309 | + fclose(f); | |
| 310 | +} | |
| 311 | + | |
| 312 | +void video_decode_example(const char *outfilename, const char *filename) | |
| 313 | +{ | |
| 314 | + AVCodec *codec; | |
| 315 | + AVCodecContext *c= NULL; | |
| 316 | + int frame, size, got_picture, len; | |
| 317 | + FILE *f; | |
| 318 | + AVFrame *picture; | |
| 319 | + uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE], *inbuf_ptr; | |
| 320 | + char buf[1024]; | |
| 321 | + | |
| 322 | + /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */ | |
| 323 | + memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE); | |
| 324 | + | |
| 325 | + printf("Video decoding\n"); | |
| 326 | + | |
| 327 | + /* find the mpeg1 video decoder */ | |
| 328 | + codec = avcodec_find_decoder(CODEC_ID_MPEG1VIDEO); | |
| 329 | + if (!codec) { | |
| 330 | + fprintf(stderr, "codec not found\n"); | |
| 331 | + exit(1); | |
| 332 | + } | |
| 333 | + | |
| 334 | + c= avcodec_alloc_context(); | |
| 335 | + picture= avcodec_alloc_frame(); | |
| 336 | + | |
| 337 | + if(codec->capabilities&CODEC_CAP_TRUNCATED) | |
| 338 | + c->flags|= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */ | |
| 339 | + | |
| 340 | + /* For some codecs, such as msmpeg4 and mpeg4, width and height | |
| 341 | + MUST be initialized there because this information is not | |
| 342 | + available in the bitstream. */ | |
| 343 | + | |
| 344 | + /* open it */ | |
| 345 | + if (avcodec_open(c, codec) < 0) { | |
| 346 | + fprintf(stderr, "could not open codec\n"); | |
| 347 | + exit(1); | |
| 348 | + } | |
| 349 | + | |
| 350 | + /* the codec gives us the frame size, in samples */ | |
| 351 | + | |
| 352 | + f = fopen(filename, "rb"); | |
| 353 | + if (!f) { | |
| 354 | + fprintf(stderr, "could not open %s\n", filename); | |
| 355 | + exit(1); | |
| 356 | + } | |
| 357 | + | |
| 358 | + frame = 0; | |
| 359 | + for(;;) { | |
| 360 | + size = fread(inbuf, 1, INBUF_SIZE, f); | |
| 361 | + if (size == 0) | |
| 362 | + break; | |
| 363 | + | |
| 364 | + /* NOTE1: some codecs are stream based (mpegvideo, mpegaudio) | |
| 365 | + and this is the only method to use them because you cannot | |
| 366 | + know the compressed data size before analysing it. | |
| 367 | + | |
| 368 | + BUT some other codecs (msmpeg4, mpeg4) are inherently frame | |
| 369 | + based, so you must call them with all the data for one | |
| 370 | + frame exactly. You must also initialize 'width' and | |
| 371 | + 'height' before initializing them. */ | |
| 372 | + | |
| 373 | + /* NOTE2: some codecs allow the raw parameters (frame size, | |
| 374 | + sample rate) to be changed at any frame. We handle this, so | |
| 375 | + you should also take care of it */ | |
| 376 | + | |
| 377 | + /* here, we use a stream based decoder (mpeg1video), so we | |
| 378 | + feed decoder and see if it could decode a frame */ | |
| 379 | + inbuf_ptr = inbuf; | |
| 380 | + while (size > 0) { | |
| 381 | + len = avcodec_decode_video(c, picture, &got_picture, | |
| 382 | + inbuf_ptr, size); | |
| 383 | + if (len < 0) { | |
| 384 | + fprintf(stderr, "Error while decoding frame %d\n", frame); | |
| 385 | + exit(1); | |
| 386 | + } | |
| 387 | + if (got_picture) { | |
| 388 | + printf("saving frame %3d\n", frame); | |
| 389 | + fflush(stdout); | |
| 390 | + | |
| 391 | + /* the picture is allocated by the decoder. no need to | |
| 392 | + free it */ | |
| 393 | + snprintf(buf, sizeof(buf), outfilename, frame); | |
| 394 | + pgm_save(picture->data[0], picture->linesize[0], | |
| 395 | + c->width, c->height, buf); | |
| 396 | + frame++; | |
| 397 | + } | |
| 398 | + size -= len; | |
| 399 | + inbuf_ptr += len; | |
| 400 | + } | |
| 401 | + } | |
| 402 | + | |
| 403 | + /* some codecs, such as MPEG, transmit the I and P frame with a | |
| 404 | + latency of one frame. You must do the following to have a | |
| 405 | + chance to get the last frame of the video */ | |
| 406 | + len = avcodec_decode_video(c, picture, &got_picture, | |
| 407 | + NULL, 0); | |
| 408 | + if (got_picture) { | |
| 409 | + printf("saving last frame %3d\n", frame); | |
| 410 | + fflush(stdout); | |
| 411 | + | |
| 412 | + /* the picture is allocated by the decoder. no need to | |
| 413 | + free it */ | |
| 414 | + snprintf(buf, sizeof(buf), outfilename, frame); | |
| 415 | + pgm_save(picture->data[0], picture->linesize[0], | |
| 416 | + c->width, c->height, buf); | |
| 417 | + frame++; | |
| 418 | + } | |
| 419 | + | |
| 420 | + fclose(f); | |
| 421 | + | |
| 422 | + avcodec_close(c); | |
| 423 | + av_free(c); | |
| 424 | + av_free(picture); | |
| 425 | + printf("\n"); | |
| 426 | +} | |
| 427 | + | |
| 428 | +int main(int argc, char **argv) | |
| 429 | +{ | |
| 430 | + const char *filename; | |
| 431 | + | |
| 432 | + /* must be called before using avcodec lib */ | |
| 433 | + avcodec_init(); | |
| 434 | + | |
| 435 | + /* register all the codecs */ | |
| 436 | + avcodec_register_all(); | |
| 437 | + | |
| 438 | + if (argc <= 1) { | |
| 439 | + audio_encode_example("/tmp/test.mp2"); | |
| 440 | + audio_decode_example("/tmp/test.sw", "/tmp/test.mp2"); | |
| 441 | + | |
| 442 | + video_encode_example("/tmp/test.mpg"); | |
| 443 | + filename = "/tmp/test.mpg"; | |
| 444 | + } else { | |
| 445 | + filename = argv[1]; | |
| 446 | + } | |
| 447 | + | |
| 448 | + // audio_decode_example("/tmp/test.sw", filename); | |
| 449 | + video_decode_example("/tmp/test%d.pgm", filename); | |
| 450 | + | |
| 451 | + return 0; | |
| 452 | +} | |