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
  41 /**************************************************************/
  42 /* audio output */
  43
  44 float t, tincr, tincr2;
  45 int16_t *samples;
  46 uint8_t *audio_outbuf;
  47 int audio_outbuf_size;
  48 int audio_input_frame_size;
  49
  50 /*
  51  * add an audio output stream
  52  */
  53 AVStream *add_audio_stream(AVFormatContext *oc, int codec_id)
  54 {
  55     AVCodecContext *c;
  56     AVStream *st;
  57
  58     st = av_new_stream(oc, 1);
  59     if (!st) {
  60         fprintf(stderr, "Could not alloc stream\n");
  61         exit(1);
  62     }
  63
  64     c = &st->codec;
  65     c->codec_id = codec_id;
  66     c->codec_type = CODEC_TYPE_AUDIO;
  67
  68     /* put sample parameters */
  69     c->bit_rate = 64000;
  70     c->sample_rate = 44100;
  71     c->channels = 2;
  72     return st;
  73 }
  74
  75 void open_audio(AVFormatContext *oc, AVStream *st)
  76 {
  77     AVCodecContext *c;
  78     AVCodec *codec;
  79
  80     c = &st->codec;
  81
  82     /* find the audio encoder */
  83     codec = avcodec_find_encoder(c->codec_id);
  84     if (!codec) {
  85         fprintf(stderr, "codec not found\n");
  86         exit(1);
  87     }
  88
  89     /* open it */
  90     if (avcodec_open(c, codec) < 0) {
  91         fprintf(stderr, "could not open codec\n");
  92         exit(1);
  93     }
  94
  95     /* init signal generator */
  96     t = 0;
  97     tincr = 2 * M_PI * 110.0 / c->sample_rate;
  98     /* increment frequency by 110 Hz per second */
  99     tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
 100
 101     audio_outbuf_size = 10000;
 102     audio_outbuf = malloc(audio_outbuf_size);
 103
 104     /* ugly hack for PCM codecs (will be removed ASAP with new PCM
 105        support to compute the input frame size in samples */
 106     if (c->frame_size <= 1) {
 107         audio_input_frame_size = audio_outbuf_size / c->channels;
 108         switch(st->codec.codec_id) {
 109         case CODEC_ID_PCM_S16LE:
 110         case CODEC_ID_PCM_S16BE:
 111         case CODEC_ID_PCM_U16LE:
 112         case CODEC_ID_PCM_U16BE:
 113             audio_input_frame_size >>= 1;
 114             break;
 115         default:
 116             break;
 117         }
 118     } else {
 119         audio_input_frame_size = c->frame_size;
 120     }
 121     samples = malloc(audio_input_frame_size * 2 * c->channels);
 122 }
 123
 124 /* prepare a 16 bit dummy audio frame of 'frame_size' samples and
 125    'nb_channels' channels */
 126 void get_audio_frame(int16_t *samples, int frame_size, int nb_channels)
 127 {
 128     int j, i, v;
 129     int16_t *q;
 130
 131     q = samples;
 132     for(j=0;j<frame_size;j++) {
 133         v = (int)(sin(t) * 10000);
 134         for(i = 0; i < nb_channels; i++)
 135             *q++ = v;
 136         t += tincr;
 137         tincr += tincr2;
 138     }
 139 }
 140
 141 void write_audio_frame(AVFormatContext *oc, AVStream *st)
 142 {
 143     int out_size;
 144     AVCodecContext *c;
 145
 146
 147     c = &st->codec;
 148
 149     get_audio_frame(samples, audio_input_frame_size, c->channels);
 150
 151     out_size = avcodec_encode_audio(c, audio_outbuf, audio_outbuf_size, samples);
 152
 153     /* write the compressed frame in the media file */
 154     if (av_write_frame(oc, st->index, audio_outbuf, out_size) != 0) {
 155         fprintf(stderr, "Error while writing audio frame\n");
 156         exit(1);
 157     }
 158 }
 159
 160 void close_audio(AVFormatContext *oc, AVStream *st)
 161 {
 162     avcodec_close(&st->codec);
 163
 164     av_free(samples);
 165     av_free(audio_outbuf);
 166 }
 167
 168 /**************************************************************/
 169 /* video output */
 170
 171 AVFrame *picture, *tmp_picture;
 172 uint8_t *video_outbuf;
 173 int frame_count, video_outbuf_size;
 174
 175 /* add a video output stream */
 176 AVStream *add_video_stream(AVFormatContext *oc, int codec_id)
 177 {
 178     AVCodecContext *c;
 179     AVStream *st;
 180
 181     st = av_new_stream(oc, 0);
 182     if (!st) {
 183         fprintf(stderr, "Could not alloc stream\n");
 184         exit(1);
 185     }
 186
 187     c = &st->codec;
 188     c->codec_id = codec_id;
 189     c->codec_type = CODEC_TYPE_VIDEO;
 190
 191     /* put sample parameters */
 192     c->bit_rate = 400000;
 193     /* resolution must be a multiple of two */
 194     c->width = 352;
 195     c->height = 288;
 196     /* frames per second */
 197     c->frame_rate = STREAM_FRAME_RATE;
 198     c->frame_rate_base = 1;
 199     c->gop_size = 12; /* emit one intra frame every twelve frames at most */
 200     if (c->codec_id == CODEC_ID_MPEG1VIDEO ||
 201         c->codec_id == CODEC_ID_MPEG2VIDEO) {
 202         /* just for testing, we also add B frames */
 203         c->max_b_frames = 2;
 204     }
 205     // some formats want stream headers to be seperate
 206     if(!strcmp(oc->oformat->name, "mp4") || !strcmp(oc->oformat->name, "mov") || !strcmp(oc->oformat->name, "3gp"))
 207         c->flags |= CODEC_FLAG_GLOBAL_HEADER;
 208
 209     return st;
 210 }
 211
 212 AVFrame *alloc_picture(int pix_fmt, int width, int height)
 213 {
 214     AVFrame *picture;
 215     uint8_t *picture_buf;
 216     int size;
 217
 218     picture = avcodec_alloc_frame();
 219     if (!picture)
 220         return NULL;
 221     size = avpicture_get_size(pix_fmt, width, height);
 222     picture_buf = malloc(size);
 223     if (!picture_buf) {
 224         av_free(picture);
 225         return NULL;
 226     }
 227     avpicture_fill((AVPicture *)picture, picture_buf,
 228                    pix_fmt, width, height);
 229     return picture;
 230 }
 231
 232 void open_video(AVFormatContext *oc, AVStream *st)
 233 {
 234     AVCodec *codec;
 235     AVCodecContext *c;
 236
 237     c = &st->codec;
 238
 239     /* find the video encoder */
 240     codec = avcodec_find_encoder(c->codec_id);
 241     if (!codec) {
 242         fprintf(stderr, "codec not found\n");
 243         exit(1);
 244     }
 245
 246     /* open the codec */
 247     if (avcodec_open(c, codec) < 0) {
 248         fprintf(stderr, "could not open codec\n");
 249         exit(1);
 250     }
 251
 252     video_outbuf = NULL;
 253     if (!(oc->oformat->flags & AVFMT_RAWPICTURE)) {
 254         /* allocate output buffer */
 255         /* XXX: API change will be done */
 256         video_outbuf_size = 200000;
 257         video_outbuf = malloc(video_outbuf_size);
 258     }
 259
 260     /* allocate the encoded raw picture */
 261     picture = alloc_picture(c->pix_fmt, c->width, c->height);
 262     if (!picture) {
 263         fprintf(stderr, "Could not allocate picture\n");
 264         exit(1);
 265     }
 266
 267     /* if the output format is not YUV420P, then a temporary YUV420P
 268        picture is needed too. It is then converted to the required
 269        output format */
 270     tmp_picture = NULL;
 271     if (c->pix_fmt != PIX_FMT_YUV420P) {
 272         tmp_picture = alloc_picture(PIX_FMT_YUV420P, c->width, c->height);
 273         if (!tmp_picture) {
 274             fprintf(stderr, "Could not allocate temporary picture\n");
 275             exit(1);
 276         }
 277     }
 278 }
 279
 280 /* prepare a dummy image */
 281 void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
 282 {
 283     int x, y, i;
 284
 285     i = frame_index;
 286
 287     /* Y */
 288     for(y=0;y<height;y++) {
 289         for(x=0;x<width;x++) {
 290             pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
 291         }
 292     }
 293
 294     /* Cb and Cr */
 295     for(y=0;y<height/2;y++) {
 296         for(x=0;x<width/2;x++) {
 297             pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
 298             pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
 299         }
 300     }
 301 }
 302
 303 void write_video_frame(AVFormatContext *oc, AVStream *st)
 304 {
 305     int out_size, ret;
 306     AVCodecContext *c;
 307     AVFrame *picture_ptr;
 308
 309     c = &st->codec;
 310
 311     if (frame_count >= STREAM_NB_FRAMES) {
 312         /* no more frame to compress. The codec has a latency of a few
 313            frames if using B frames, so we get the last frames by
 314            passing a NULL picture */
 315         picture_ptr = NULL;
 316     } else {
 317         if (c->pix_fmt != PIX_FMT_YUV420P) {
 318             /* as we only generate a YUV420P picture, we must convert it
 319                to the codec pixel format if needed */
 320             fill_yuv_image(tmp_picture, frame_count, c->width, c->height);
 321             img_convert((AVPicture *)picture, c->pix_fmt,
 322                         (AVPicture *)tmp_picture, PIX_FMT_YUV420P,
 323                         c->width, c->height);
 324         } else {
 325             fill_yuv_image(picture, frame_count, c->width, c->height);
 326         }
 327         picture_ptr = picture;
 328     }
 329
 330
 331     if (oc->oformat->flags & AVFMT_RAWPICTURE) {
 332         /* raw video case. The API will change slightly in the near
 333            futur for that */
 334         ret = av_write_frame(oc, st->index,
 335                        (uint8_t *)picture_ptr, sizeof(AVPicture));
 336     } else {
 337         /* encode the image */
 338         out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture_ptr);
 339         /* if zero size, it means the image was buffered */
 340         if (out_size != 0) {
 341             /* write the compressed frame in the media file */
 342             /* XXX: in case of B frames, the pts is not yet valid */
 343             ret = av_write_frame(oc, st->index, video_outbuf, out_size);
 344         } else {
 345             ret = 0;
 346         }
 347     }
 348     if (ret != 0) {
 349         fprintf(stderr, "Error while writing video frame\n");
 350         exit(1);
 351     }
 352     frame_count++;
 353 }
 354
 355 void close_video(AVFormatContext *oc, AVStream *st)
 356 {
 357     avcodec_close(&st->codec);
 358     av_free(picture->data[0]);
 359     av_free(picture);
 360     if (tmp_picture) {
 361         av_free(tmp_picture->data[0]);
 362         av_free(tmp_picture);
 363     }
 364     av_free(video_outbuf);
 365 }
 366
 367 /**************************************************************/
 368 /* media file output */
 369
 370 int main(int argc, char **argv)
 371 {
 372     const char *filename;
 373     AVOutputFormat *fmt;
 374     AVFormatContext *oc;
 375     AVStream *audio_st, *video_st;
 376     double audio_pts, video_pts;
 377     int i;
 378
 379     /* initialize libavcodec, and register all codecs and formats */
 380     av_register_all();
 381
 382     if (argc != 2) {
 383         printf("usage: %s output_file\n"
 384                "API example program to output a media file with libavformat.\n"
 385                "The output format is automatically guessed according to the file extension.\n"
 386                "Raw images can also be output by using '%%d' in the filename\n"
 387                "\n", argv[0]);
 388         exit(1);
 389     }
 390
 391     filename = argv[1];
 392
 393     /* auto detect the output format from the name. default is
 394        mpeg. */
 395     fmt = guess_format(NULL, filename, NULL);
 396     if (!fmt) {
 397         printf("Could not deduce output format from file extension: using MPEG.\n");
 398         fmt = guess_format("mpeg", NULL, NULL);
 399     }
 400     if (!fmt) {
 401         fprintf(stderr, "Could not find suitable output format\n");
 402         exit(1);
 403     }
 404
 405     /* allocate the output media context */
 406     oc = av_mallocz(sizeof(AVFormatContext));
 407     if (!oc) {
 408         fprintf(stderr, "Memory error\n");
 409         exit(1);
 410     }
 411     oc->oformat = fmt;
 412     snprintf(oc->filename, sizeof(oc->filename), "%s", filename);
 413
 414     /* add the audio and video streams using the default format codecs
 415        and initialize the codecs */
 416     video_st = NULL;
 417     audio_st = NULL;
 418     if (fmt->video_codec != CODEC_ID_NONE) {
 419         video_st = add_video_stream(oc, fmt->video_codec);
 420     }
 421     if (fmt->audio_codec != CODEC_ID_NONE) {
 422         audio_st = add_audio_stream(oc, fmt->audio_codec);
 423     }
 424
 425     /* set the output parameters (must be done even if no
 426        parameters). */
 427     if (av_set_parameters(oc, NULL) < 0) {
 428         fprintf(stderr, "Invalid output format parameters\n");
 429         exit(1);
 430     }
 431
 432     dump_format(oc, 0, filename, 1);
 433
 434     /* now that all the parameters are set, we can open the audio and
 435        video codecs and allocate the necessary encode buffers */
 436     if (video_st)
 437         open_video(oc, video_st);
 438     if (audio_st)
 439         open_audio(oc, audio_st);
 440
 441     /* open the output file, if needed */
 442     if (!(fmt->flags & AVFMT_NOFILE)) {
 443         if (url_fopen(&oc->pb, filename, URL_WRONLY) < 0) {
 444             fprintf(stderr, "Could not open '%s'\n", filename);
 445             exit(1);
 446         }
 447     }
 448
 449     /* write the stream header, if any */
 450     av_write_header(oc);
 451
 452     for(;;) {
 453         /* compute current audio and video time */
 454         if (audio_st)
 455             audio_pts = (double)audio_st->pts.val * oc->pts_num / oc->pts_den;
 456         else
 457             audio_pts = 0.0;
 458
 459         if (video_st)
 460             video_pts = (double)video_st->pts.val * oc->pts_num / oc->pts_den;
 461         else
 462             video_pts = 0.0;
 463
 464         if ((!audio_st || audio_pts >= STREAM_DURATION) &&
 465             (!video_st || video_pts >= STREAM_DURATION))
 466             break;
 467
 468         /* write interleaved audio and video frames */
 469         if (!video_st || (video_st && audio_st && audio_pts < video_pts)) {
 470             write_audio_frame(oc, audio_st);
 471         } else {
 472             write_video_frame(oc, video_st);
 473         }
 474     }
 475
 476     /* close each codec */
 477     if (video_st)
 478         close_video(oc, video_st);
 479     if (audio_st)
 480         close_audio(oc, audio_st);
 481
 482     /* write the trailer, if any */
 483     av_write_trailer(oc);
 484
 485     /* free the streams */
 486     for(i = 0; i < oc->nb_streams; i++) {
 487         av_freep(&oc->streams[i]);
 488     }
 489
 490     if (!(fmt->flags & AVFMT_NOFILE)) {
 491         /* close the output file */
 492         url_fclose(&oc->pb);
 493     }
 494
 495     /* free the stream */
 496     av_free(oc);
 497
 498     return 0;
 499 }