output_example.c

   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
  45 float t, tincr, tincr2;
  46 int16_t *samples;
  47 uint8_t *audio_outbuf;
  48 int audio_outbuf_size;
  49 int audio_input_frame_size;
  50
  51 /*
  52  * add an audio output stream
  53  */
  54 static 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
  76 static 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 */
 127 static 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
 142 static 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
 166 static 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
 177 AVFrame *picture, *tmp_picture;
 178 uint8_t *video_outbuf;
 179 int frame_count, video_outbuf_size;
 180
 181 /* add a video output stream */
 182 static 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
 227 static 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
 247 static 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 */
 296 static 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
 318 static 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
 383 static 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
 398 int 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 }