libavformat/output-example.c

   1 /*
   2  * Copyright (c) 2003 Fabrice Bellard
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  20  * THE SOFTWARE.
  21  */
  22
  23 /**
  24  * @file
  25  * libavformat API example.
  26  *
  27  * @example libavformat/output-example.c
  28  * Output a media file in any supported libavformat format.
  29  * The default codecs are used.
  30  */
  31
  32 #include <stdlib.h>
  33 #include <stdio.h>
  34 #include <string.h>
  35 #include <math.h>
  36
  37 #include "libavutil/mathematics.h"
  38 #include "libavformat/avformat.h"
  39 #include "libswscale/swscale.h"
  40
  41 /* 5 seconds stream duration */
  42 #define STREAM_DURATION   5.0
  43 #define STREAM_FRAME_RATE 25 /* 25 images/s */
  44 #define STREAM_NB_FRAMES  ((int)(STREAM_DURATION * STREAM_FRAME_RATE))
  45 #define STREAM_PIX_FMT    AV_PIX_FMT_YUV420P /* default pix_fmt */
  46
  47 static int sws_flags = SWS_BICUBIC;
  48
  49 /**************************************************************/
  50 /* audio output */
  51
  52 static float t, tincr, tincr2;
  53 static int16_t *samples;
  54 static int audio_input_frame_size;
  55
  56 /*
  57  * add an audio output stream
  58  */
  59 static AVStream *add_audio_stream(AVFormatContext *oc, enum AVCodecID codec_id)
  60 {
  61     AVCodecContext *c;
  62     AVStream *st;
  63     AVCodec *codec;
  64
  65     /* find the audio encoder */
  66     codec = avcodec_find_encoder(codec_id);
  67     if (!codec) {
  68         fprintf(stderr, "codec not found\n");
  69         exit(1);
  70     }
  71
  72     st = avformat_new_stream(oc, codec);
  73     if (!st) {
  74         fprintf(stderr, "Could not alloc stream\n");
  75         exit(1);
  76     }
  77
  78     c = st->codec;
  79
  80     /* put sample parameters */
  81     c->sample_fmt  = AV_SAMPLE_FMT_S16;
  82     c->bit_rate    = 64000;
  83     c->sample_rate = 44100;
  84     c->channels    = 2;
  85
  86     // some formats want stream headers to be separate
  87     if (oc->oformat->flags & AVFMT_GLOBALHEADER)
  88         c->flags |= CODEC_FLAG_GLOBAL_HEADER;
  89
  90     return st;
  91 }
  92
  93 static void open_audio(AVFormatContext *oc, AVStream *st)
  94 {
  95     AVCodecContext *c;
  96
  97     c = st->codec;
  98
  99     /* open it */
 100     if (avcodec_open2(c, NULL, NULL) < 0) {
 101         fprintf(stderr, "could not open codec\n");
 102         exit(1);
 103     }
 104
 105     /* init signal generator */
 106     t     = 0;
 107     tincr = 2 * M_PI * 110.0 / c->sample_rate;
 108     /* increment frequency by 110 Hz per second */
 109     tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
 110
 111     if (c->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE)
 112         audio_input_frame_size = 10000;
 113     else
 114         audio_input_frame_size = c->frame_size;
 115     samples = av_malloc(audio_input_frame_size *
 116                         av_get_bytes_per_sample(c->sample_fmt) *
 117                         c->channels);
 118 }
 119
 120 /* Prepare a 16 bit dummy audio frame of 'frame_size' samples and
 121  * 'nb_channels' channels. */
 122 static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels)
 123 {
 124     int j, i, v;
 125     int16_t *q;
 126
 127     q = samples;
 128     for (j = 0; j < frame_size; j++) {
 129         v = (int)(sin(t) * 10000);
 130         for (i = 0; i < nb_channels; i++)
 131             *q++ = v;
 132         t     += tincr;
 133         tincr += tincr2;
 134     }
 135 }
 136
 137 static void write_audio_frame(AVFormatContext *oc, AVStream *st)
 138 {
 139     AVCodecContext *c;
 140     AVPacket pkt = { 0 }; // data and size must be 0;
 141     AVFrame *frame = avcodec_alloc_frame();
 142     int got_packet;
 143
 144     av_init_packet(&pkt);
 145     c = st->codec;
 146
 147     get_audio_frame(samples, audio_input_frame_size, c->channels);
 148     frame->nb_samples = audio_input_frame_size;
 149     avcodec_fill_audio_frame(frame, c->channels, c->sample_fmt,
 150                              (uint8_t *)samples,
 151                              audio_input_frame_size *
 152                              av_get_bytes_per_sample(c->sample_fmt) *
 153                              c->channels, 1);
 154
 155     avcodec_encode_audio2(c, &pkt, frame, &got_packet);
 156     if (!got_packet)
 157         return;
 158
 159     pkt.stream_index = st->index;
 160
 161     /* Write the compressed frame to the media file. */
 162     if (av_interleaved_write_frame(oc, &pkt) != 0) {
 163         fprintf(stderr, "Error while writing audio frame\n");
 164         exit(1);
 165     }
 166     avcodec_free_frame(&frame);
 167 }
 168
 169 static void close_audio(AVFormatContext *oc, AVStream *st)
 170 {
 171     avcodec_close(st->codec);
 172
 173     av_free(samples);
 174 }
 175
 176 /**************************************************************/
 177 /* video output */
 178
 179 static AVFrame *picture, *tmp_picture;
 180 static uint8_t *video_outbuf;
 181 static int frame_count, video_outbuf_size;
 182
 183 /* Add a video output stream. */
 184 static AVStream *add_video_stream(AVFormatContext *oc, enum AVCodecID codec_id)
 185 {
 186     AVCodecContext *c;
 187     AVStream *st;
 188     AVCodec *codec;
 189
 190     /* find the video encoder */
 191     codec = avcodec_find_encoder(codec_id);
 192     if (!codec) {
 193         fprintf(stderr, "codec not found\n");
 194         exit(1);
 195     }
 196
 197     st = avformat_new_stream(oc, codec);
 198     if (!st) {
 199         fprintf(stderr, "Could not alloc stream\n");
 200         exit(1);
 201     }
 202
 203     c = st->codec;
 204
 205     /* Put sample parameters. */
 206     c->bit_rate = 400000;
 207     /* Resolution must be a multiple of two. */
 208     c->width    = 352;
 209     c->height   = 288;
 210     /* timebase: This is the fundamental unit of time (in seconds) in terms
 211      * of which frame timestamps are represented. For fixed-fps content,
 212      * timebase should be 1/framerate and timestamp increments should be
 213      * identical to 1. */
 214     c->time_base.den = STREAM_FRAME_RATE;
 215     c->time_base.num = 1;
 216     c->gop_size      = 12; /* emit one intra frame every twelve frames at most */
 217     c->pix_fmt       = STREAM_PIX_FMT;
 218     if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
 219         /* just for testing, we also add B frames */
 220         c->max_b_frames = 2;
 221     }
 222     if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
 223         /* Needed to avoid using macroblocks in which some coeffs overflow.
 224          * This does not happen with normal video, it just happens here as
 225          * the motion of the chroma plane does not match the luma plane. */
 226         c->mb_decision = 2;
 227     }
 228     /* Some formats want stream headers to be separate. */
 229     if (oc->oformat->flags & AVFMT_GLOBALHEADER)
 230         c->flags |= CODEC_FLAG_GLOBAL_HEADER;
 231
 232     return st;
 233 }
 234
 235 static AVFrame *alloc_picture(enum AVPixelFormat pix_fmt, int width, int height)
 236 {
 237     AVFrame *picture;
 238     uint8_t *picture_buf;
 239     int size;
 240
 241     picture = avcodec_alloc_frame();
 242     if (!picture)
 243         return NULL;
 244     size        = avpicture_get_size(pix_fmt, width, height);
 245     picture_buf = av_malloc(size);
 246     if (!picture_buf) {
 247         av_free(picture);
 248         return NULL;
 249     }
 250     avpicture_fill((AVPicture *)picture, picture_buf,
 251                    pix_fmt, width, height);
 252     return picture;
 253 }
 254
 255 static void open_video(AVFormatContext *oc, AVStream *st)
 256 {
 257     AVCodecContext *c;
 258
 259     c = st->codec;
 260
 261     /* open the codec */
 262     if (avcodec_open2(c, NULL, NULL) < 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         /* Buffers passed into lav* can be allocated any way you prefer,
 272          * as long as they're aligned enough for the architecture, and
 273          * they're freed appropriately (such as using av_free for buffers
 274          * allocated with av_malloc). */
 275         video_outbuf_size = 200000;
 276         video_outbuf      = av_malloc(video_outbuf_size);
 277     }
 278
 279     /* Allocate the encoded raw picture. */
 280     picture = alloc_picture(c->pix_fmt, c->width, c->height);
 281     if (!picture) {
 282         fprintf(stderr, "Could not allocate picture\n");
 283         exit(1);
 284     }
 285
 286     /* If the output format is not YUV420P, then a temporary YUV420P
 287      * picture is needed too. It is then converted to the required
 288      * output format. */
 289     tmp_picture = NULL;
 290     if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
 291         tmp_picture = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height);
 292         if (!tmp_picture) {
 293             fprintf(stderr, "Could not allocate temporary picture\n");
 294             exit(1);
 295         }
 296     }
 297 }
 298
 299 /* Prepare a dummy image. */
 300 static void fill_yuv_image(AVFrame *pict, int frame_index,
 301                            int width, int height)
 302 {
 303     int x, y, i;
 304
 305     i = frame_index;
 306
 307     /* Y */
 308     for (y = 0; y < height; y++)
 309         for (x = 0; x < width; x++)
 310             pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
 311
 312     /* Cb and Cr */
 313     for (y = 0; y < height / 2; y++) {
 314         for (x = 0; x < width / 2; x++) {
 315             pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
 316             pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
 317         }
 318     }
 319 }
 320
 321 static void write_video_frame(AVFormatContext *oc, AVStream *st)
 322 {
 323     int out_size, ret;
 324     AVCodecContext *c;
 325     static struct SwsContext *img_convert_ctx;
 326
 327     c = st->codec;
 328
 329     if (frame_count >= STREAM_NB_FRAMES) {
 330         /* No more frames to compress. The codec has a latency of a few
 331          * frames if using B-frames, so we get the last frames by
 332          * passing the same picture again. */
 333     } else {
 334         if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
 335             /* as we only generate a YUV420P picture, we must convert it
 336              * to the codec pixel format if needed */
 337             if (img_convert_ctx == NULL) {
 338                 img_convert_ctx = sws_getContext(c->width, c->height,
 339                                                  AV_PIX_FMT_YUV420P,
 340                                                  c->width, c->height,
 341                                                  c->pix_fmt,
 342                                                  sws_flags, NULL, NULL, NULL);
 343                 if (img_convert_ctx == NULL) {
 344                     fprintf(stderr,
 345                             "Cannot initialize the conversion context\n");
 346                     exit(1);
 347                 }
 348             }
 349             fill_yuv_image(tmp_picture, frame_count, c->width, c->height);
 350             sws_scale(img_convert_ctx, tmp_picture->data, tmp_picture->linesize,
 351                       0, c->height, picture->data, picture->linesize);
 352         } else {
 353             fill_yuv_image(picture, frame_count, c->width, c->height);
 354         }
 355     }
 356
 357     if (oc->oformat->flags & AVFMT_RAWPICTURE) {
 358         /* Raw video case - the API will change slightly in the near
 359          * future for that. */
 360         AVPacket pkt;
 361         av_init_packet(&pkt);
 362
 363         pkt.flags        |= AV_PKT_FLAG_KEY;
 364         pkt.stream_index  = st->index;
 365         pkt.data          = (uint8_t *)picture;
 366         pkt.size          = sizeof(AVPicture);
 367
 368         ret = av_interleaved_write_frame(oc, &pkt);
 369     } else {
 370         /* encode the image */
 371         out_size = avcodec_encode_video(c, video_outbuf,
 372                                         video_outbuf_size, picture);
 373         /* If size is zero, it means the image was buffered. */
 374         if (out_size > 0) {
 375             AVPacket pkt;
 376             av_init_packet(&pkt);
 377
 378             if (c->coded_frame->pts != AV_NOPTS_VALUE)
 379                 pkt.pts = av_rescale_q(c->coded_frame->pts,
 380                                        c->time_base, st->time_base);
 381             if (c->coded_frame->key_frame)
 382                 pkt.flags |= AV_PKT_FLAG_KEY;
 383             pkt.stream_index = st->index;
 384             pkt.data         = video_outbuf;
 385             pkt.size         = out_size;
 386
 387             /* Write the compressed frame to the media file. */
 388             ret = av_interleaved_write_frame(oc, &pkt);
 389         } else {
 390             ret = 0;
 391         }
 392     }
 393     if (ret != 0) {
 394         fprintf(stderr, "Error while writing video frame\n");
 395         exit(1);
 396     }
 397     frame_count++;
 398 }
 399
 400 static void close_video(AVFormatContext *oc, AVStream *st)
 401 {
 402     avcodec_close(st->codec);
 403     av_free(picture->data[0]);
 404     av_free(picture);
 405     if (tmp_picture) {
 406         av_free(tmp_picture->data[0]);
 407         av_free(tmp_picture);
 408     }
 409     av_free(video_outbuf);
 410 }
 411
 412 /**************************************************************/
 413 /* media file output */
 414
 415 int main(int argc, char **argv)
 416 {
 417     const char *filename;
 418     AVOutputFormat *fmt;
 419     AVFormatContext *oc;
 420     AVStream *audio_st, *video_st;
 421     double audio_pts, video_pts;
 422     int i;
 423
 424     /* Initialize libavcodec, and register all codecs and formats. */
 425     av_register_all();
 426
 427     if (argc != 2) {
 428         printf("usage: %s output_file\n"
 429                "API example program to output a media file with libavformat.\n"
 430                "The output format is automatically guessed according to the file extension.\n"
 431                "Raw images can also be output by using '%%d' in the filename\n"
 432                "\n", argv[0]);
 433         return 1;
 434     }
 435
 436     filename = argv[1];
 437
 438     /* Autodetect the output format from the name. default is MPEG. */
 439     fmt = av_guess_format(NULL, filename, NULL);
 440     if (!fmt) {
 441         printf("Could not deduce output format from file extension: using MPEG.\n");
 442         fmt = av_guess_format("mpeg", NULL, NULL);
 443     }
 444     if (!fmt) {
 445         fprintf(stderr, "Could not find suitable output format\n");
 446         return 1;
 447     }
 448
 449     /* Allocate the output media context. */
 450     oc = avformat_alloc_context();
 451     if (!oc) {
 452         fprintf(stderr, "Memory error\n");
 453         return 1;
 454     }
 455     oc->oformat = fmt;
 456     snprintf(oc->filename, sizeof(oc->filename), "%s", filename);
 457
 458     /* Add the audio and video streams using the default format codecs
 459      * and initialize the codecs. */
 460     video_st = NULL;
 461     audio_st = NULL;
 462     if (fmt->video_codec != AV_CODEC_ID_NONE) {
 463         video_st = add_video_stream(oc, fmt->video_codec);
 464     }
 465     if (fmt->audio_codec != AV_CODEC_ID_NONE) {
 466         audio_st = add_audio_stream(oc, fmt->audio_codec);
 467     }
 468
 469     /* Now that all the parameters are set, we can open the audio and
 470      * video codecs and allocate the necessary encode buffers. */
 471     if (video_st)
 472         open_video(oc, video_st);
 473     if (audio_st)
 474         open_audio(oc, audio_st);
 475
 476     av_dump_format(oc, 0, filename, 1);
 477
 478     /* open the output file, if needed */
 479     if (!(fmt->flags & AVFMT_NOFILE)) {
 480         if (avio_open(&oc->pb, filename, AVIO_FLAG_WRITE) < 0) {
 481             fprintf(stderr, "Could not open '%s'\n", filename);
 482             return 1;
 483         }
 484     }
 485
 486     /* Write the stream header, if any. */
 487     avformat_write_header(oc, NULL);
 488
 489     for (;;) {
 490         /* Compute current audio and video time. */
 491         if (audio_st)
 492             audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den;
 493         else
 494             audio_pts = 0.0;
 495
 496         if (video_st)
 497             video_pts = (double)video_st->pts.val * video_st->time_base.num /
 498                         video_st->time_base.den;
 499         else
 500             video_pts = 0.0;
 501
 502         if ((!audio_st || audio_pts >= STREAM_DURATION) &&
 503             (!video_st || video_pts >= STREAM_DURATION))
 504             break;
 505
 506         /* write interleaved audio and video frames */
 507         if (!video_st || (video_st && audio_st && audio_pts < video_pts)) {
 508             write_audio_frame(oc, audio_st);
 509         } else {
 510             write_video_frame(oc, video_st);
 511         }
 512     }
 513
 514     /* Write the trailer, if any. The trailer must be written before you
 515      * close the CodecContexts open when you wrote the header; otherwise
 516      * av_write_trailer() may try to use memory that was freed on
 517      * av_codec_close(). */
 518     av_write_trailer(oc);
 519
 520     /* Close each codec. */
 521     if (video_st)
 522         close_video(oc, video_st);
 523     if (audio_st)
 524         close_audio(oc, audio_st);
 525
 526     /* Free the streams. */
 527     for (i = 0; i < oc->nb_streams; i++) {
 528         av_freep(&oc->streams[i]->codec);
 529         av_freep(&oc->streams[i]);
 530     }
 531
 532     if (!(fmt->flags & AVFMT_NOFILE))
 533         /* Close the output file. */
 534         avio_close(oc->pb);
 535
 536     /* free the stream */
 537     av_free(oc);
 538
 539     return 0;
 540 }