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 <math.h>
  28
  29 #include "avformat.h"
  30
  31 /* 5 seconds stream duration */
  32 #define STREAM_DURATION 5.0
  33
  34
  35 /**************************************************************/
  36 /* audio output */
  37
  38 float t, tincr, tincr2;
  39 int16_t *samples;
  40 uint8_t *audio_outbuf;
  41 int audio_outbuf_size;
  42 int audio_input_frame_size;
  43
  44 /*
  45  * add an audio output stream
  46  */
  47 AVStream *add_audio_stream(AVFormatContext *oc, int codec_id)
  48 {
  49     AVCodecContext *c;
  50     AVStream *st;
  51
  52     st = av_new_stream(oc, 1);
  53     if (!st) {
  54         fprintf(stderr, "Could not alloc stream\n");
  55         exit(1);
  56     }
  57
  58     c = &st->codec;
  59     c->codec_id = codec_id;
  60     c->codec_type = CODEC_TYPE_AUDIO;
  61
  62     /* put sample parameters */
  63     c->bit_rate = 64000;
  64     c->sample_rate = 44100;
  65     c->channels = 2;
  66     return st;
  67 }
  68
  69 void open_audio(AVFormatContext *oc, AVStream *st)
  70 {
  71     AVCodecContext *c;
  72     AVCodec *codec;
  73
  74     c = &st->codec;
  75
  76     /* find the audio encoder */
  77     codec = avcodec_find_encoder(c->codec_id);
  78     if (!codec) {
  79         fprintf(stderr, "codec not found\n");
  80         exit(1);
  81     }
  82
  83     /* open it */
  84     if (avcodec_open(c, codec) < 0) {
  85         fprintf(stderr, "could not open codec\n");
  86         exit(1);
  87     }
  88
  89     /* init signal generator */
  90     t = 0;
  91     tincr = 2 * M_PI * 110.0 / c->sample_rate;
  92     /* increment frequency by 110 Hz per second */
  93     tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
  94
  95     audio_outbuf_size = 10000;
  96     audio_outbuf = malloc(audio_outbuf_size);
  97
  98     /* ugly hack for PCM codecs (will be removed ASAP with new PCM
  99        support to compute the input frame size in samples */
 100     if (c->frame_size <= 1) {
 101         audio_input_frame_size = audio_outbuf_size / c->channels;
 102         switch(st->codec.codec_id) {
 103         case CODEC_ID_PCM_S16LE:
 104         case CODEC_ID_PCM_S16BE:
 105         case CODEC_ID_PCM_U16LE:
 106         case CODEC_ID_PCM_U16BE:
 107             audio_input_frame_size >>= 1;
 108             break;
 109         default:
 110             break;
 111         }
 112     } else {
 113         audio_input_frame_size = c->frame_size;
 114     }
 115     samples = malloc(audio_input_frame_size * 2 * c->channels);
 116 }
 117
 118 void write_audio_frame(AVFormatContext *oc, AVStream *st)
 119 {
 120     int j, out_size;
 121     AVCodecContext *c;
 122
 123
 124     c = &st->codec;
 125
 126     for(j=0;j<audio_input_frame_size;j++) {
 127         samples[2*j] = (int)(sin(t) * 10000);
 128         samples[2*j+1] = samples[2*j];
 129         t += tincr;
 130         tincr += tincr2;
 131     }
 132
 133     out_size = avcodec_encode_audio(c, audio_outbuf, audio_outbuf_size, samples);
 134
 135     /* write the compressed frame in the media file */
 136     if (av_write_frame(oc, st->index, audio_outbuf, out_size) != 0) {
 137         fprintf(stderr, "Error while writing audio frame\n");
 138         exit(1);
 139     }
 140 }
 141
 142 void close_audio(AVFormatContext *oc, AVStream *st)
 143 {
 144     avcodec_close(&st->codec);
 145
 146     av_free(samples);
 147     av_free(audio_outbuf);
 148 }
 149
 150 /**************************************************************/
 151 /* video output */
 152
 153 AVFrame *picture, *tmp_picture;
 154 uint8_t *video_outbuf;
 155 int frame_count, video_outbuf_size;
 156
 157 /* add a video output stream */
 158 AVStream *add_video_stream(AVFormatContext *oc, int codec_id)
 159 {
 160     AVCodecContext *c;
 161     AVStream *st;
 162
 163     st = av_new_stream(oc, 0);
 164     if (!st) {
 165         fprintf(stderr, "Could not alloc stream\n");
 166         exit(1);
 167     }
 168
 169     c = &st->codec;
 170     c->codec_id = codec_id;
 171     c->codec_type = CODEC_TYPE_VIDEO;
 172
 173     /* put sample parameters */
 174     c->bit_rate = 400000;
 175     /* resolution must be a multiple of two */
 176     c->width = 352;
 177     c->height = 288;
 178     /* frames per second */
 179     c->frame_rate = 25;
 180     c->frame_rate_base= 1;
 181     c->gop_size = 12; /* emit one intra frame every twelve frames */
 182
 183     return st;
 184 }
 185
 186 AVFrame *alloc_picture(int pix_fmt, int width, int height)
 187 {
 188     AVFrame *picture;
 189     uint8_t *picture_buf;
 190     int size;
 191
 192     picture = avcodec_alloc_frame();
 193     if (!picture)
 194         return NULL;
 195     size = avpicture_get_size(pix_fmt, width, height);
 196     picture_buf = malloc(size);
 197     if (!picture_buf) {
 198         av_free(picture);
 199         return NULL;
 200     }
 201     avpicture_fill((AVPicture *)picture, picture_buf,
 202                    pix_fmt, width, height);
 203     return picture;
 204 }
 205
 206 void open_video(AVFormatContext *oc, AVStream *st)
 207 {
 208     AVCodec *codec;
 209     AVCodecContext *c;
 210
 211     c = &st->codec;
 212
 213     /* find the video encoder */
 214     codec = avcodec_find_encoder(c->codec_id);
 215     if (!codec) {
 216         fprintf(stderr, "codec not found\n");
 217         exit(1);
 218     }
 219
 220     /* open the codec */
 221     if (avcodec_open(c, codec) < 0) {
 222         fprintf(stderr, "could not open codec\n");
 223         exit(1);
 224     }
 225
 226     video_outbuf = NULL;
 227     if (!(oc->oformat->flags & AVFMT_RAWPICTURE)) {
 228         /* allocate output buffer */
 229         /* XXX: API change will be done */
 230         video_outbuf_size = 200000;
 231         video_outbuf = malloc(video_outbuf_size);
 232     }
 233
 234     /* allocate the encoded raw picture */
 235     picture = alloc_picture(c->pix_fmt, c->width, c->height);
 236     if (!picture) {
 237         fprintf(stderr, "Could not allocate picture\n");
 238         exit(1);
 239     }
 240
 241     /* if the output format is not YUV420P, then a temporary YUV420P
 242        picture is needed too. It is then converted to the required
 243        output format */
 244     tmp_picture = NULL;
 245     if (c->pix_fmt != PIX_FMT_YUV420P) {
 246         tmp_picture = alloc_picture(PIX_FMT_YUV420P, c->width, c->height);
 247         if (!tmp_picture) {
 248             fprintf(stderr, "Could not allocate temporary picture\n");
 249             exit(1);
 250         }
 251     }
 252 }
 253
 254 /* prepare a dummy image */
 255 void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
 256 {
 257     int x, y, i;
 258
 259     i = frame_index;
 260
 261     /* Y */
 262     for(y=0;y<height;y++) {
 263         for(x=0;x<width;x++) {
 264             pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
 265         }
 266     }
 267
 268     /* Cb and Cr */
 269     for(y=0;y<height/2;y++) {
 270         for(x=0;x<width/2;x++) {
 271             pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
 272             pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
 273         }
 274     }
 275 }
 276
 277 void write_video_frame(AVFormatContext *oc, AVStream *st)
 278 {
 279     int out_size, ret;
 280     AVCodecContext *c;
 281
 282     c = &st->codec;
 283
 284     if (c->pix_fmt != PIX_FMT_YUV420P) {
 285         /* as we only generate a YUV420P picture, we must convert it
 286            to the codec pixel format if needed */
 287         fill_yuv_image(tmp_picture, frame_count, c->width, c->height);
 288         img_convert((AVPicture *)picture, c->pix_fmt,
 289                     (AVPicture *)tmp_picture, PIX_FMT_YUV420P,
 290                     c->width, c->height);
 291     } else {
 292         fill_yuv_image(picture, frame_count, c->width, c->height);
 293     }
 294
 295
 296     if (oc->oformat->flags & AVFMT_RAWPICTURE) {
 297         /* raw video case. The API will change slightly in the near
 298            futur for that */
 299         ret = av_write_frame(oc, st->index,
 300                        (uint8_t *)picture, sizeof(AVPicture));
 301     } else {
 302         /* encode the image */
 303         out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture);
 304
 305         /* write the compressed frame in the media file */
 306         ret = av_write_frame(oc, st->index, video_outbuf, out_size);
 307     }
 308     if (ret != 0) {
 309         fprintf(stderr, "Error while writing video frame\n");
 310         exit(1);
 311     }
 312     frame_count++;
 313 }
 314
 315 void close_video(AVFormatContext *oc, AVStream *st)
 316 {
 317     avcodec_close(&st->codec);
 318     av_free(picture->data[0]);
 319     av_free(picture);
 320     if (tmp_picture) {
 321         av_free(tmp_picture->data[0]);
 322         av_free(tmp_picture);
 323     }
 324     av_free(video_outbuf);
 325 }
 326
 327 /**************************************************************/
 328 /* media file output */
 329
 330 int main(int argc, char **argv)
 331 {
 332     const char *filename;
 333     AVOutputFormat *fmt;
 334     AVFormatContext *oc;
 335     AVStream *audio_st, *video_st;
 336     double audio_pts, video_pts;
 337     int i;
 338
 339     /* initialize libavcodec, and register all codecs and formats */
 340     av_register_all();
 341
 342     if (argc != 2) {
 343         printf("usage: %s output_file\n"
 344                "API example program to output a media file with libavformat.\n"
 345                "The output format is automatically guessed according to the file extension.\n"
 346                "Raw images can also be output by using '%%d' in the filename\n"
 347                "\n", argv[0]);
 348         exit(1);
 349     }
 350
 351     filename = argv[1];
 352
 353     /* auto detect the output format from the name. default is
 354        mpeg. */
 355     fmt = guess_format(NULL, filename, NULL);
 356     if (!fmt) {
 357         printf("Could not deduce output format from file extension: using MPEG.\n");
 358         fmt = guess_format("mpeg", NULL, NULL);
 359     }
 360     if (!fmt) {
 361         fprintf(stderr, "Could not find suitable output format\n");
 362         exit(1);
 363     }
 364
 365     /* allocate the output media context */
 366     oc = av_mallocz(sizeof(AVFormatContext));
 367     if (!oc) {
 368         fprintf(stderr, "Memory error\n");
 369         exit(1);
 370     }
 371     oc->oformat = fmt;
 372     snprintf(oc->filename, sizeof(oc->filename), "%s", filename);
 373
 374     /* add the audio and video streams using the default format codecs
 375        and initialize the codecs */
 376     video_st = NULL;
 377     audio_st = NULL;
 378     if (fmt->video_codec != CODEC_ID_NONE) {
 379         video_st = add_video_stream(oc, fmt->video_codec);
 380     }
 381     if (fmt->audio_codec != CODEC_ID_NONE) {
 382         audio_st = add_audio_stream(oc, fmt->audio_codec);
 383     }
 384
 385     /* set the output parameters (must be done even if no
 386        parameters). */
 387     if (av_set_parameters(oc, NULL) < 0) {
 388         fprintf(stderr, "Invalid output format parameters\n");
 389         exit(1);
 390     }
 391
 392     dump_format(oc, 0, filename, 1);
 393
 394     /* now that all the parameters are set, we can open the audio and
 395        video codecs and allocate the necessary encode buffers */
 396     if (video_st)
 397         open_video(oc, video_st);
 398     if (audio_st)
 399         open_audio(oc, audio_st);
 400
 401     /* open the output file, if needed */
 402     if (!(fmt->flags & AVFMT_NOFILE)) {
 403         if (url_fopen(&oc->pb, filename, URL_WRONLY) < 0) {
 404             fprintf(stderr, "Could not open '%s'\n", filename);
 405             exit(1);
 406         }
 407     }
 408
 409     /* write the stream header, if any */
 410     av_write_header(oc);
 411
 412     for(;;) {
 413         /* compute current audio and video time */
 414         if (audio_st)
 415             audio_pts = (double)audio_st->pts.val * oc->pts_num / oc->pts_den;
 416         else
 417             audio_pts = 0.0;
 418
 419         if (video_st)
 420             video_pts = (double)video_st->pts.val * oc->pts_num / oc->pts_den;
 421         else
 422             video_pts = 0.0;
 423
 424         if ((!audio_st || audio_pts >= STREAM_DURATION) &&
 425             (!video_st || video_pts >= STREAM_DURATION))
 426             break;
 427
 428         /* write interleaved audio and video frames */
 429         if (!video_st || (video_st && audio_st && audio_pts < video_pts)) {
 430             write_audio_frame(oc, audio_st);
 431         } else {
 432             write_video_frame(oc, video_st);
 433         }
 434     }
 435
 436     /* close each codec */
 437     if (video_st)
 438         close_video(oc, video_st);
 439     if (audio_st)
 440         close_audio(oc, audio_st);
 441
 442     /* write the trailer, if any */
 443     av_write_trailer(oc);
 444
 445     /* free the streams */
 446     for(i = 0; i < oc->nb_streams; i++) {
 447         av_freep(&oc->streams[i]);
 448     }
 449
 450     if (!(fmt->flags & AVFMT_NOFILE)) {
 451         /* close the output file */
 452         url_fclose(&oc->pb);
 453     }
 454
 455     /* free the stream */
 456     av_free(oc);
 457
 458     return 0;
 459 }