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#include "libavformat/avformat.h" 31#include "libswscale/swscale.h" 32 33#undef exit 34 35/* 5 seconds stream duration */ 36#define STREAM_DURATION 5.0 37#define STREAM_FRAME_RATE 25 /* 25 images/s */ 38#define STREAM_NB_FRAMES ((int)(STREAM_DURATION * STREAM_FRAME_RATE)) 39#define STREAM_PIX_FMT PIX_FMT_YUV420P /* default pix_fmt */ 40 41static int sws_flags = SWS_BICUBIC; 42 43/**************************************************************/ 44/* audio output */ 45 46float t, tincr, tincr2; 47int16_t *samples; 48uint8_t *audio_outbuf; 49int audio_outbuf_size; 50int audio_input_frame_size; 51 52/* 53 * add an audio output stream 54 */ 55static AVStream *add_audio_stream(AVFormatContext *oc, enum CodecID codec_id) 56{ 57 AVCodecContext *c; 58 AVStream *st; 59 60 st = av_new_stream(oc, 1); 61 if (!st) { 62 fprintf(stderr, "Could not alloc stream\n"); 63 exit(1); 64 } 65 66 c = st->codec; 67 c->codec_id = codec_id; 68 c->codec_type = AVMEDIA_TYPE_AUDIO; 69 70 /* put sample parameters */ 71 c->bit_rate = 64000; 72 c->sample_rate = 44100; 73 c->channels = 2; 74 75 // some formats want stream headers to be separate 76 if(oc->oformat->flags & AVFMT_GLOBALHEADER) 77 c->flags |= CODEC_FLAG_GLOBAL_HEADER; 78 79 return st; 80} 81 82static void open_audio(AVFormatContext *oc, AVStream *st) 83{ 84 AVCodecContext *c; 85 AVCodec *codec; 86 87 c = st->codec; 88 89 /* find the audio encoder */ 90 codec = avcodec_find_encoder(c->codec_id); 91 if (!codec) { 92 fprintf(stderr, "codec not found\n"); 93 exit(1); 94 } 95 96 /* open it */ 97 if (avcodec_open(c, codec) < 0) { 98 fprintf(stderr, "could not open codec\n"); 99 exit(1); 100 } 101 102 /* init signal generator */ 103 t = 0; 104 tincr = 2 * M_PI * 110.0 / c->sample_rate; 105 /* increment frequency by 110 Hz per second */ 106 tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate; 107 108 audio_outbuf_size = 10000; 109 audio_outbuf = av_malloc(audio_outbuf_size); 110 111 /* ugly hack for PCM codecs (will be removed ASAP with new PCM 112 support to compute the input frame size in samples */ 113 if (c->frame_size <= 1) { 114 audio_input_frame_size = audio_outbuf_size / c->channels; 115 switch(st->codec->codec_id) { 116 case CODEC_ID_PCM_S16LE: 117 case CODEC_ID_PCM_S16BE: 118 case CODEC_ID_PCM_U16LE: 119 case CODEC_ID_PCM_U16BE: 120 audio_input_frame_size >>= 1; 121 break; 122 default: 123 break; 124 } 125 } else { 126 audio_input_frame_size = c->frame_size; 127 } 128 samples = av_malloc(audio_input_frame_size * 2 * c->channels); 129} 130 131/* prepare a 16 bit dummy audio frame of 'frame_size' samples and 132 'nb_channels' channels */ 133static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels) 134{ 135 int j, i, v; 136 int16_t *q; 137 138 q = samples; 139 for(j=0;j<frame_size;j++) { 140 v = (int)(sin(t) * 10000); 141 for(i = 0; i < nb_channels; i++) 142 *q++ = v; 143 t += tincr; 144 tincr += tincr2; 145 } 146} 147 148static void write_audio_frame(AVFormatContext *oc, AVStream *st) 149{ 150 AVCodecContext *c; 151 AVPacket pkt; 152 av_init_packet(&pkt); 153 154 c = st->codec; 155 156 get_audio_frame(samples, audio_input_frame_size, c->channels); 157 158 pkt.size= avcodec_encode_audio(c, audio_outbuf, audio_outbuf_size, samples); 159 160 if (c->coded_frame && c->coded_frame->pts != AV_NOPTS_VALUE) 161 pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base); 162 pkt.flags |= AV_PKT_FLAG_KEY; 163 pkt.stream_index= st->index; 164 pkt.data= audio_outbuf; 165 166 /* write the compressed frame in the media file */ 167 if (av_interleaved_write_frame(oc, &pkt) != 0) { 168 fprintf(stderr, "Error while writing audio frame\n"); 169 exit(1); 170 } 171} 172 173static void close_audio(AVFormatContext *oc, AVStream *st) 174{ 175 avcodec_close(st->codec); 176 177 av_free(samples); 178 av_free(audio_outbuf); 179} 180 181/**************************************************************/ 182/* video output */ 183 184AVFrame *picture, *tmp_picture; 185uint8_t *video_outbuf; 186int frame_count, video_outbuf_size; 187 188/* add a video output stream */ 189static AVStream *add_video_stream(AVFormatContext *oc, enum CodecID codec_id) 190{ 191 AVCodecContext *c; 192 AVStream *st; 193 194 st = av_new_stream(oc, 0); 195 if (!st) { 196 fprintf(stderr, "Could not alloc stream\n"); 197 exit(1); 198 } 199 200 c = st->codec; 201 c->codec_id = codec_id; 202 c->codec_type = AVMEDIA_TYPE_VIDEO; 203 204 /* put sample parameters */ 205 c->bit_rate = 400000; 206 /* resolution must be a multiple of two */ 207 c->width = 352; 208 c->height = 288; 209 /* time base: this is the fundamental unit of time (in seconds) in terms 210 of which frame timestamps are represented. for fixed-fps content, 211 timebase should be 1/framerate and timestamp increments should be 212 identically 1. */ 213 c->time_base.den = STREAM_FRAME_RATE; 214 c->time_base.num = 1; 215 c->gop_size = 12; /* emit one intra frame every twelve frames at most */ 216 c->pix_fmt = STREAM_PIX_FMT; 217 if (c->codec_id == CODEC_ID_MPEG2VIDEO) { 218 /* just for testing, we also add B frames */ 219 c->max_b_frames = 2; 220 } 221 if (c->codec_id == CODEC_ID_MPEG1VIDEO){ 222 /* Needed to avoid using macroblocks in which some coeffs overflow. 223 This does not happen with normal video, it just happens here as 224 the motion of the chroma plane does not match the luma plane. */ 225 c->mb_decision=2; 226 } 227 // some formats want stream headers to be separate 228 if(oc->oformat->flags & AVFMT_GLOBALHEADER) 229 c->flags |= CODEC_FLAG_GLOBAL_HEADER; 230 231 return st; 232} 233 234static AVFrame *alloc_picture(enum PixelFormat pix_fmt, int width, int height) 235{ 236 AVFrame *picture; 237 uint8_t *picture_buf; 238 int size; 239 240 picture = avcodec_alloc_frame(); 241 if (!picture) 242 return NULL; 243 size = avpicture_get_size(pix_fmt, width, height); 244 picture_buf = av_malloc(size); 245 if (!picture_buf) { 246 av_free(picture); 247 return NULL; 248 } 249 avpicture_fill((AVPicture *)picture, picture_buf, 250 pix_fmt, width, height); 251 return picture; 252} 253 254static void open_video(AVFormatContext *oc, AVStream *st) 255{ 256 AVCodec *codec; 257 AVCodecContext *c; 258 259 c = st->codec; 260 261 /* find the video encoder */ 262 codec = avcodec_find_encoder(c->codec_id); 263 if (!codec) { 264 fprintf(stderr, "codec not found\n"); 265 exit(1); 266 } 267 268 /* open the codec */ 269 if (avcodec_open(c, codec) < 0) { 270 fprintf(stderr, "could not open codec\n"); 271 exit(1); 272 } 273 274 video_outbuf = NULL; 275 if (!(oc->oformat->flags & AVFMT_RAWPICTURE)) { 276 /* allocate output buffer */ 277 /* XXX: API change will be done */ 278 /* buffers passed into lav* can be allocated any way you prefer, 279 as long as they're aligned enough for the architecture, and 280 they're freed appropriately (such as using av_free for buffers 281 allocated with av_malloc) */ 282 video_outbuf_size = 200000; 283 video_outbuf = av_malloc(video_outbuf_size); 284 } 285 286 /* allocate the encoded raw picture */ 287 picture = alloc_picture(c->pix_fmt, c->width, c->height); 288 if (!picture) { 289 fprintf(stderr, "Could not allocate picture\n"); 290 exit(1); 291 } 292 293 /* if the output format is not YUV420P, then a temporary YUV420P 294 picture is needed too. It is then converted to the required 295 output format */ 296 tmp_picture = NULL; 297 if (c->pix_fmt != PIX_FMT_YUV420P) { 298 tmp_picture = alloc_picture(PIX_FMT_YUV420P, c->width, c->height); 299 if (!tmp_picture) { 300 fprintf(stderr, "Could not allocate temporary picture\n"); 301 exit(1); 302 } 303 } 304} 305 306/* prepare a dummy image */ 307static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height) 308{ 309 int x, y, i; 310 311 i = frame_index; 312 313 /* Y */ 314 for(y=0;y<height;y++) { 315 for(x=0;x<width;x++) { 316 pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3; 317 } 318 } 319 320 /* Cb and Cr */ 321 for(y=0;y<height/2;y++) { 322 for(x=0;x<width/2;x++) { 323 pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2; 324 pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5; 325 } 326 } 327} 328 329static void write_video_frame(AVFormatContext *oc, AVStream *st) 330{ 331 int out_size, ret; 332 AVCodecContext *c; 333 static struct SwsContext *img_convert_ctx; 334 335 c = st->codec; 336 337 if (frame_count >= STREAM_NB_FRAMES) { 338 /* no more frame to compress. The codec has a latency of a few 339 frames if using B frames, so we get the last frames by 340 passing the same picture again */ 341 } else { 342 if (c->pix_fmt != PIX_FMT_YUV420P) { 343 /* as we only generate a YUV420P picture, we must convert it 344 to the codec pixel format if needed */ 345 if (img_convert_ctx == NULL) { 346 img_convert_ctx = sws_getContext(c->width, c->height, 347 PIX_FMT_YUV420P, 348 c->width, c->height, 349 c->pix_fmt, 350 sws_flags, NULL, NULL, NULL); 351 if (img_convert_ctx == NULL) { 352 fprintf(stderr, "Cannot initialize the conversion context\n"); 353 exit(1); 354 } 355 } 356 fill_yuv_image(tmp_picture, frame_count, c->width, c->height); 357 sws_scale(img_convert_ctx, tmp_picture->data, tmp_picture->linesize, 358 0, c->height, picture->data, picture->linesize); 359 } else { 360 fill_yuv_image(picture, frame_count, c->width, c->height); 361 } 362 } 363 364 365 if (oc->oformat->flags & AVFMT_RAWPICTURE) { 366 /* raw video case. The API will change slightly in the near 367 futur for that */ 368 AVPacket pkt; 369 av_init_packet(&pkt); 370 371 pkt.flags |= AV_PKT_FLAG_KEY; 372 pkt.stream_index= st->index; 373 pkt.data= (uint8_t *)picture; 374 pkt.size= sizeof(AVPicture); 375 376 ret = av_interleaved_write_frame(oc, &pkt); 377 } else { 378 /* encode the image */ 379 out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture); 380 /* if zero size, it means the image was buffered */ 381 if (out_size > 0) { 382 AVPacket pkt; 383 av_init_packet(&pkt); 384 385 if (c->coded_frame->pts != AV_NOPTS_VALUE) 386 pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base); 387 if(c->coded_frame->key_frame) 388 pkt.flags |= AV_PKT_FLAG_KEY; 389 pkt.stream_index= st->index; 390 pkt.data= video_outbuf; 391 pkt.size= out_size; 392 393 /* write the compressed frame in the media file */ 394 ret = av_interleaved_write_frame(oc, &pkt); 395 } else { 396 ret = 0; 397 } 398 } 399 if (ret != 0) { 400 fprintf(stderr, "Error while writing video frame\n"); 401 exit(1); 402 } 403 frame_count++; 404} 405 406static void close_video(AVFormatContext *oc, AVStream *st) 407{ 408 avcodec_close(st->codec); 409 av_free(picture->data[0]); 410 av_free(picture); 411 if (tmp_picture) { 412 av_free(tmp_picture->data[0]); 413 av_free(tmp_picture); 414 } 415 av_free(video_outbuf); 416} 417 418/**************************************************************/ 419/* media file output */ 420 421int main(int argc, char **argv) 422{ 423 const char *filename; 424 AVOutputFormat *fmt; 425 AVFormatContext *oc; 426 AVStream *audio_st, *video_st; 427 double audio_pts, video_pts; 428 int i; 429 430 /* initialize libavcodec, and register all codecs and formats */ 431 av_register_all(); 432 433 if (argc != 2) { 434 printf("usage: %s output_file\n" 435 "API example program to output a media file with libavformat.\n" 436 "The output format is automatically guessed according to the file extension.\n" 437 "Raw images can also be output by using '%%d' in the filename\n" 438 "\n", argv[0]); 439 exit(1); 440 } 441 442 filename = argv[1]; 443 444 /* auto detect the output format from the name. default is 445 mpeg. */ 446 fmt = av_guess_format(NULL, filename, NULL); 447 if (!fmt) { 448 printf("Could not deduce output format from file extension: using MPEG.\n"); 449 fmt = av_guess_format("mpeg", NULL, NULL); 450 } 451 if (!fmt) { 452 fprintf(stderr, "Could not find suitable output format\n"); 453 exit(1); 454 } 455 456 /* allocate the output media context */ 457 oc = avformat_alloc_context(); 458 if (!oc) { 459 fprintf(stderr, "Memory error\n"); 460 exit(1); 461 } 462 oc->oformat = fmt; 463 snprintf(oc->filename, sizeof(oc->filename), "%s", filename); 464 465 /* add the audio and video streams using the default format codecs 466 and initialize the codecs */ 467 video_st = NULL; 468 audio_st = NULL; 469 if (fmt->video_codec != CODEC_ID_NONE) { 470 video_st = add_video_stream(oc, fmt->video_codec); 471 } 472 if (fmt->audio_codec != CODEC_ID_NONE) { 473 audio_st = add_audio_stream(oc, fmt->audio_codec); 474 } 475 476 /* set the output parameters (must be done even if no 477 parameters). */ 478 if (av_set_parameters(oc, NULL) < 0) { 479 fprintf(stderr, "Invalid output format parameters\n"); 480 exit(1); 481 } 482 483 dump_format(oc, 0, filename, 1); 484 485 /* now that all the parameters are set, we can open the audio and 486 video codecs and allocate the necessary encode buffers */ 487 if (video_st) 488 open_video(oc, video_st); 489 if (audio_st) 490 open_audio(oc, audio_st); 491 492 /* open the output file, if needed */ 493 if (!(fmt->flags & AVFMT_NOFILE)) { 494 if (url_fopen(&oc->pb, filename, URL_WRONLY) < 0) { 495 fprintf(stderr, "Could not open '%s'\n", filename); 496 exit(1); 497 } 498 } 499 500 /* write the stream header, if any */ 501 av_write_header(oc); 502 503 for(;;) { 504 /* compute current audio and video time */ 505 if (audio_st) 506 audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den; 507 else 508 audio_pts = 0.0; 509 510 if (video_st) 511 video_pts = (double)video_st->pts.val * video_st->time_base.num / video_st->time_base.den; 512 else 513 video_pts = 0.0; 514 515 if ((!audio_st || audio_pts >= STREAM_DURATION) && 516 (!video_st || video_pts >= STREAM_DURATION)) 517 break; 518 519 /* write interleaved audio and video frames */ 520 if (!video_st || (video_st && audio_st && audio_pts < video_pts)) { 521 write_audio_frame(oc, audio_st); 522 } else { 523 write_video_frame(oc, video_st); 524 } 525 } 526 527 /* write the trailer, if any. the trailer must be written 528 * before you close the CodecContexts open when you wrote the 529 * header; otherwise write_trailer may try to use memory that 530 * was freed on av_codec_close() */ 531 av_write_trailer(oc); 532 533 /* close each codec */ 534 if (video_st) 535 close_video(oc, video_st); 536 if (audio_st) 537 close_audio(oc, audio_st); 538 539 /* free the streams */ 540 for(i = 0; i < oc->nb_streams; i++) { 541 av_freep(&oc->streams[i]->codec); 542 av_freep(&oc->streams[i]); 543 } 544 545 if (!(fmt->flags & AVFMT_NOFILE)) { 546 /* close the output file */ 547 url_fclose(oc->pb); 548 } 549 550 /* free the stream */ 551 av_free(oc); 552 553 return 0; 554} 555