| 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 | * Output a media file in any supported libavformat format. The default |
| 28 | * codecs are used. |
| 29 | * @example muxing.c |
| 30 | */ |
| 31 | |
| 32 | #include <stdlib.h> |
| 33 | #include <stdio.h> |
| 34 | #include <string.h> |
| 35 | #include <math.h> |
| 36 | |
| 37 | #include <libavutil/avassert.h> |
| 38 | #include <libavutil/channel_layout.h> |
| 39 | #include <libavutil/opt.h> |
| 40 | #include <libavutil/mathematics.h> |
| 41 | #include <libavutil/timestamp.h> |
| 42 | #include <libavformat/avformat.h> |
| 43 | #include <libswscale/swscale.h> |
| 44 | #include <libswresample/swresample.h> |
| 45 | |
| 46 | #define STREAM_DURATION 10.0 |
| 47 | #define STREAM_FRAME_RATE 25 /* 25 images/s */ |
| 48 | #define STREAM_PIX_FMT AV_PIX_FMT_YUV420P /* default pix_fmt */ |
| 49 | |
| 50 | #define SCALE_FLAGS SWS_BICUBIC |
| 51 | |
| 52 | // a wrapper around a single output AVStream |
| 53 | typedef struct OutputStream { |
| 54 | AVStream *st; |
| 55 | |
| 56 | /* pts of the next frame that will be generated */ |
| 57 | int64_t next_pts; |
| 58 | int samples_count; |
| 59 | |
| 60 | AVFrame *frame; |
| 61 | AVFrame *tmp_frame; |
| 62 | |
| 63 | float t, tincr, tincr2; |
| 64 | |
| 65 | struct SwsContext *sws_ctx; |
| 66 | struct SwrContext *swr_ctx; |
| 67 | } OutputStream; |
| 68 | |
| 69 | static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt) |
| 70 | { |
| 71 | AVRational *time_base = &fmt_ctx->streams[pkt->stream_index]->time_base; |
| 72 | |
| 73 | printf("pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n", |
| 74 | av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base), |
| 75 | av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base), |
| 76 | av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, time_base), |
| 77 | pkt->stream_index); |
| 78 | } |
| 79 | |
| 80 | static int write_frame(AVFormatContext *fmt_ctx, const AVRational *time_base, AVStream *st, AVPacket *pkt) |
| 81 | { |
| 82 | /* rescale output packet timestamp values from codec to stream timebase */ |
| 83 | av_packet_rescale_ts(pkt, *time_base, st->time_base); |
| 84 | pkt->stream_index = st->index; |
| 85 | |
| 86 | /* Write the compressed frame to the media file. */ |
| 87 | log_packet(fmt_ctx, pkt); |
| 88 | return av_interleaved_write_frame(fmt_ctx, pkt); |
| 89 | } |
| 90 | |
| 91 | /* Add an output stream. */ |
| 92 | static void add_stream(OutputStream *ost, AVFormatContext *oc, |
| 93 | AVCodec **codec, |
| 94 | enum AVCodecID codec_id) |
| 95 | { |
| 96 | AVCodecContext *c; |
| 97 | int i; |
| 98 | |
| 99 | /* find the encoder */ |
| 100 | *codec = avcodec_find_encoder(codec_id); |
| 101 | if (!(*codec)) { |
| 102 | fprintf(stderr, "Could not find encoder for '%s'\n", |
| 103 | avcodec_get_name(codec_id)); |
| 104 | exit(1); |
| 105 | } |
| 106 | |
| 107 | ost->st = avformat_new_stream(oc, *codec); |
| 108 | if (!ost->st) { |
| 109 | fprintf(stderr, "Could not allocate stream\n"); |
| 110 | exit(1); |
| 111 | } |
| 112 | ost->st->id = oc->nb_streams-1; |
| 113 | c = ost->st->codec; |
| 114 | |
| 115 | switch ((*codec)->type) { |
| 116 | case AVMEDIA_TYPE_AUDIO: |
| 117 | c->sample_fmt = (*codec)->sample_fmts ? |
| 118 | (*codec)->sample_fmts[0] : AV_SAMPLE_FMT_FLTP; |
| 119 | c->bit_rate = 64000; |
| 120 | c->sample_rate = 44100; |
| 121 | if ((*codec)->supported_samplerates) { |
| 122 | c->sample_rate = (*codec)->supported_samplerates[0]; |
| 123 | for (i = 0; (*codec)->supported_samplerates[i]; i++) { |
| 124 | if ((*codec)->supported_samplerates[i] == 44100) |
| 125 | c->sample_rate = 44100; |
| 126 | } |
| 127 | } |
| 128 | c->channels = av_get_channel_layout_nb_channels(c->channel_layout); |
| 129 | c->channel_layout = AV_CH_LAYOUT_STEREO; |
| 130 | if ((*codec)->channel_layouts) { |
| 131 | c->channel_layout = (*codec)->channel_layouts[0]; |
| 132 | for (i = 0; (*codec)->channel_layouts[i]; i++) { |
| 133 | if ((*codec)->channel_layouts[i] == AV_CH_LAYOUT_STEREO) |
| 134 | c->channel_layout = AV_CH_LAYOUT_STEREO; |
| 135 | } |
| 136 | } |
| 137 | c->channels = av_get_channel_layout_nb_channels(c->channel_layout); |
| 138 | ost->st->time_base = (AVRational){ 1, c->sample_rate }; |
| 139 | break; |
| 140 | |
| 141 | case AVMEDIA_TYPE_VIDEO: |
| 142 | c->codec_id = codec_id; |
| 143 | |
| 144 | c->bit_rate = 400000; |
| 145 | /* Resolution must be a multiple of two. */ |
| 146 | c->width = 352; |
| 147 | c->height = 288; |
| 148 | /* timebase: This is the fundamental unit of time (in seconds) in terms |
| 149 | * of which frame timestamps are represented. For fixed-fps content, |
| 150 | * timebase should be 1/framerate and timestamp increments should be |
| 151 | * identical to 1. */ |
| 152 | ost->st->time_base = (AVRational){ 1, STREAM_FRAME_RATE }; |
| 153 | c->time_base = ost->st->time_base; |
| 154 | |
| 155 | c->gop_size = 12; /* emit one intra frame every twelve frames at most */ |
| 156 | c->pix_fmt = STREAM_PIX_FMT; |
| 157 | if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) { |
| 158 | /* just for testing, we also add B frames */ |
| 159 | c->max_b_frames = 2; |
| 160 | } |
| 161 | if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) { |
| 162 | /* Needed to avoid using macroblocks in which some coeffs overflow. |
| 163 | * This does not happen with normal video, it just happens here as |
| 164 | * the motion of the chroma plane does not match the luma plane. */ |
| 165 | c->mb_decision = 2; |
| 166 | } |
| 167 | break; |
| 168 | |
| 169 | default: |
| 170 | break; |
| 171 | } |
| 172 | |
| 173 | /* Some formats want stream headers to be separate. */ |
| 174 | if (oc->oformat->flags & AVFMT_GLOBALHEADER) |
| 175 | c->flags |= CODEC_FLAG_GLOBAL_HEADER; |
| 176 | } |
| 177 | |
| 178 | /**************************************************************/ |
| 179 | /* audio output */ |
| 180 | |
| 181 | static AVFrame *alloc_audio_frame(enum AVSampleFormat sample_fmt, |
| 182 | uint64_t channel_layout, |
| 183 | int sample_rate, int nb_samples) |
| 184 | { |
| 185 | AVFrame *frame = av_frame_alloc(); |
| 186 | int ret; |
| 187 | |
| 188 | if (!frame) { |
| 189 | fprintf(stderr, "Error allocating an audio frame\n"); |
| 190 | exit(1); |
| 191 | } |
| 192 | |
| 193 | frame->format = sample_fmt; |
| 194 | frame->channel_layout = channel_layout; |
| 195 | frame->sample_rate = sample_rate; |
| 196 | frame->nb_samples = nb_samples; |
| 197 | |
| 198 | if (nb_samples) { |
| 199 | ret = av_frame_get_buffer(frame, 0); |
| 200 | if (ret < 0) { |
| 201 | fprintf(stderr, "Error allocating an audio buffer\n"); |
| 202 | exit(1); |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | return frame; |
| 207 | } |
| 208 | |
| 209 | static void open_audio(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg) |
| 210 | { |
| 211 | AVCodecContext *c; |
| 212 | int nb_samples; |
| 213 | int ret; |
| 214 | AVDictionary *opt = NULL; |
| 215 | |
| 216 | c = ost->st->codec; |
| 217 | |
| 218 | /* open it */ |
| 219 | av_dict_copy(&opt, opt_arg, 0); |
| 220 | ret = avcodec_open2(c, codec, &opt); |
| 221 | av_dict_free(&opt); |
| 222 | if (ret < 0) { |
| 223 | fprintf(stderr, "Could not open audio codec: %s\n", av_err2str(ret)); |
| 224 | exit(1); |
| 225 | } |
| 226 | |
| 227 | /* init signal generator */ |
| 228 | ost->t = 0; |
| 229 | ost->tincr = 2 * M_PI * 110.0 / c->sample_rate; |
| 230 | /* increment frequency by 110 Hz per second */ |
| 231 | ost->tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate; |
| 232 | |
| 233 | if (c->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE) |
| 234 | nb_samples = 10000; |
| 235 | else |
| 236 | nb_samples = c->frame_size; |
| 237 | |
| 238 | ost->frame = alloc_audio_frame(c->sample_fmt, c->channel_layout, |
| 239 | c->sample_rate, nb_samples); |
| 240 | ost->tmp_frame = alloc_audio_frame(AV_SAMPLE_FMT_S16, c->channel_layout, |
| 241 | c->sample_rate, nb_samples); |
| 242 | |
| 243 | /* create resampler context */ |
| 244 | ost->swr_ctx = swr_alloc(); |
| 245 | if (!ost->swr_ctx) { |
| 246 | fprintf(stderr, "Could not allocate resampler context\n"); |
| 247 | exit(1); |
| 248 | } |
| 249 | |
| 250 | /* set options */ |
| 251 | av_opt_set_int (ost->swr_ctx, "in_channel_count", c->channels, 0); |
| 252 | av_opt_set_int (ost->swr_ctx, "in_sample_rate", c->sample_rate, 0); |
| 253 | av_opt_set_sample_fmt(ost->swr_ctx, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0); |
| 254 | av_opt_set_int (ost->swr_ctx, "out_channel_count", c->channels, 0); |
| 255 | av_opt_set_int (ost->swr_ctx, "out_sample_rate", c->sample_rate, 0); |
| 256 | av_opt_set_sample_fmt(ost->swr_ctx, "out_sample_fmt", c->sample_fmt, 0); |
| 257 | |
| 258 | /* initialize the resampling context */ |
| 259 | if ((ret = swr_init(ost->swr_ctx)) < 0) { |
| 260 | fprintf(stderr, "Failed to initialize the resampling context\n"); |
| 261 | exit(1); |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | /* Prepare a 16 bit dummy audio frame of 'frame_size' samples and |
| 266 | * 'nb_channels' channels. */ |
| 267 | static AVFrame *get_audio_frame(OutputStream *ost) |
| 268 | { |
| 269 | AVFrame *frame = ost->tmp_frame; |
| 270 | int j, i, v; |
| 271 | int16_t *q = (int16_t*)frame->data[0]; |
| 272 | |
| 273 | /* check if we want to generate more frames */ |
| 274 | if (av_compare_ts(ost->next_pts, ost->st->codec->time_base, |
| 275 | STREAM_DURATION, (AVRational){ 1, 1 }) >= 0) |
| 276 | return NULL; |
| 277 | |
| 278 | for (j = 0; j <frame->nb_samples; j++) { |
| 279 | v = (int)(sin(ost->t) * 10000); |
| 280 | for (i = 0; i < ost->st->codec->channels; i++) |
| 281 | *q++ = v; |
| 282 | ost->t += ost->tincr; |
| 283 | ost->tincr += ost->tincr2; |
| 284 | } |
| 285 | |
| 286 | frame->pts = ost->next_pts; |
| 287 | ost->next_pts += frame->nb_samples; |
| 288 | |
| 289 | return frame; |
| 290 | } |
| 291 | |
| 292 | /* |
| 293 | * encode one audio frame and send it to the muxer |
| 294 | * return 1 when encoding is finished, 0 otherwise |
| 295 | */ |
| 296 | static int write_audio_frame(AVFormatContext *oc, OutputStream *ost) |
| 297 | { |
| 298 | AVCodecContext *c; |
| 299 | AVPacket pkt = { 0 }; // data and size must be 0; |
| 300 | AVFrame *frame; |
| 301 | int ret; |
| 302 | int got_packet; |
| 303 | int dst_nb_samples; |
| 304 | |
| 305 | av_init_packet(&pkt); |
| 306 | c = ost->st->codec; |
| 307 | |
| 308 | frame = get_audio_frame(ost); |
| 309 | |
| 310 | if (frame) { |
| 311 | /* convert samples from native format to destination codec format, using the resampler */ |
| 312 | /* compute destination number of samples */ |
| 313 | dst_nb_samples = av_rescale_rnd(swr_get_delay(ost->swr_ctx, c->sample_rate) + frame->nb_samples, |
| 314 | c->sample_rate, c->sample_rate, AV_ROUND_UP); |
| 315 | av_assert0(dst_nb_samples == frame->nb_samples); |
| 316 | |
| 317 | /* when we pass a frame to the encoder, it may keep a reference to it |
| 318 | * internally; |
| 319 | * make sure we do not overwrite it here |
| 320 | */ |
| 321 | ret = av_frame_make_writable(ost->frame); |
| 322 | if (ret < 0) |
| 323 | exit(1); |
| 324 | |
| 325 | /* convert to destination format */ |
| 326 | ret = swr_convert(ost->swr_ctx, |
| 327 | ost->frame->data, dst_nb_samples, |
| 328 | (const uint8_t **)frame->data, frame->nb_samples); |
| 329 | if (ret < 0) { |
| 330 | fprintf(stderr, "Error while converting\n"); |
| 331 | exit(1); |
| 332 | } |
| 333 | frame = ost->frame; |
| 334 | |
| 335 | frame->pts = av_rescale_q(ost->samples_count, (AVRational){1, c->sample_rate}, c->time_base); |
| 336 | ost->samples_count += dst_nb_samples; |
| 337 | } |
| 338 | |
| 339 | ret = avcodec_encode_audio2(c, &pkt, frame, &got_packet); |
| 340 | if (ret < 0) { |
| 341 | fprintf(stderr, "Error encoding audio frame: %s\n", av_err2str(ret)); |
| 342 | exit(1); |
| 343 | } |
| 344 | |
| 345 | if (got_packet) { |
| 346 | ret = write_frame(oc, &c->time_base, ost->st, &pkt); |
| 347 | if (ret < 0) { |
| 348 | fprintf(stderr, "Error while writing audio frame: %s\n", |
| 349 | av_err2str(ret)); |
| 350 | exit(1); |
| 351 | } |
| 352 | } |
| 353 | |
| 354 | return (frame || got_packet) ? 0 : 1; |
| 355 | } |
| 356 | |
| 357 | /**************************************************************/ |
| 358 | /* video output */ |
| 359 | |
| 360 | static AVFrame *alloc_picture(enum AVPixelFormat pix_fmt, int width, int height) |
| 361 | { |
| 362 | AVFrame *picture; |
| 363 | int ret; |
| 364 | |
| 365 | picture = av_frame_alloc(); |
| 366 | if (!picture) |
| 367 | return NULL; |
| 368 | |
| 369 | picture->format = pix_fmt; |
| 370 | picture->width = width; |
| 371 | picture->height = height; |
| 372 | |
| 373 | /* allocate the buffers for the frame data */ |
| 374 | ret = av_frame_get_buffer(picture, 32); |
| 375 | if (ret < 0) { |
| 376 | fprintf(stderr, "Could not allocate frame data.\n"); |
| 377 | exit(1); |
| 378 | } |
| 379 | |
| 380 | return picture; |
| 381 | } |
| 382 | |
| 383 | static void open_video(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg) |
| 384 | { |
| 385 | int ret; |
| 386 | AVCodecContext *c = ost->st->codec; |
| 387 | AVDictionary *opt = NULL; |
| 388 | |
| 389 | av_dict_copy(&opt, opt_arg, 0); |
| 390 | |
| 391 | /* open the codec */ |
| 392 | ret = avcodec_open2(c, codec, &opt); |
| 393 | av_dict_free(&opt); |
| 394 | if (ret < 0) { |
| 395 | fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret)); |
| 396 | exit(1); |
| 397 | } |
| 398 | |
| 399 | /* allocate and init a re-usable frame */ |
| 400 | ost->frame = alloc_picture(c->pix_fmt, c->width, c->height); |
| 401 | if (!ost->frame) { |
| 402 | fprintf(stderr, "Could not allocate video frame\n"); |
| 403 | exit(1); |
| 404 | } |
| 405 | |
| 406 | /* If the output format is not YUV420P, then a temporary YUV420P |
| 407 | * picture is needed too. It is then converted to the required |
| 408 | * output format. */ |
| 409 | ost->tmp_frame = NULL; |
| 410 | if (c->pix_fmt != AV_PIX_FMT_YUV420P) { |
| 411 | ost->tmp_frame = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height); |
| 412 | if (!ost->tmp_frame) { |
| 413 | fprintf(stderr, "Could not allocate temporary picture\n"); |
| 414 | exit(1); |
| 415 | } |
| 416 | } |
| 417 | } |
| 418 | |
| 419 | /* Prepare a dummy image. */ |
| 420 | static void fill_yuv_image(AVFrame *pict, int frame_index, |
| 421 | int width, int height) |
| 422 | { |
| 423 | int x, y, i, ret; |
| 424 | |
| 425 | /* when we pass a frame to the encoder, it may keep a reference to it |
| 426 | * internally; |
| 427 | * make sure we do not overwrite it here |
| 428 | */ |
| 429 | ret = av_frame_make_writable(pict); |
| 430 | if (ret < 0) |
| 431 | exit(1); |
| 432 | |
| 433 | i = frame_index; |
| 434 | |
| 435 | /* Y */ |
| 436 | for (y = 0; y < height; y++) |
| 437 | for (x = 0; x < width; x++) |
| 438 | pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3; |
| 439 | |
| 440 | /* Cb and Cr */ |
| 441 | for (y = 0; y < height / 2; y++) { |
| 442 | for (x = 0; x < width / 2; x++) { |
| 443 | pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2; |
| 444 | pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5; |
| 445 | } |
| 446 | } |
| 447 | } |
| 448 | |
| 449 | static AVFrame *get_video_frame(OutputStream *ost) |
| 450 | { |
| 451 | AVCodecContext *c = ost->st->codec; |
| 452 | |
| 453 | /* check if we want to generate more frames */ |
| 454 | if (av_compare_ts(ost->next_pts, ost->st->codec->time_base, |
| 455 | STREAM_DURATION, (AVRational){ 1, 1 }) >= 0) |
| 456 | return NULL; |
| 457 | |
| 458 | if (c->pix_fmt != AV_PIX_FMT_YUV420P) { |
| 459 | /* as we only generate a YUV420P picture, we must convert it |
| 460 | * to the codec pixel format if needed */ |
| 461 | if (!ost->sws_ctx) { |
| 462 | ost->sws_ctx = sws_getContext(c->width, c->height, |
| 463 | AV_PIX_FMT_YUV420P, |
| 464 | c->width, c->height, |
| 465 | c->pix_fmt, |
| 466 | SCALE_FLAGS, NULL, NULL, NULL); |
| 467 | if (!ost->sws_ctx) { |
| 468 | fprintf(stderr, |
| 469 | "Could not initialize the conversion context\n"); |
| 470 | exit(1); |
| 471 | } |
| 472 | } |
| 473 | fill_yuv_image(ost->tmp_frame, ost->next_pts, c->width, c->height); |
| 474 | sws_scale(ost->sws_ctx, |
| 475 | (const uint8_t * const *)ost->tmp_frame->data, ost->tmp_frame->linesize, |
| 476 | 0, c->height, ost->frame->data, ost->frame->linesize); |
| 477 | } else { |
| 478 | fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height); |
| 479 | } |
| 480 | |
| 481 | ost->frame->pts = ost->next_pts++; |
| 482 | |
| 483 | return ost->frame; |
| 484 | } |
| 485 | |
| 486 | /* |
| 487 | * encode one video frame and send it to the muxer |
| 488 | * return 1 when encoding is finished, 0 otherwise |
| 489 | */ |
| 490 | static int write_video_frame(AVFormatContext *oc, OutputStream *ost) |
| 491 | { |
| 492 | int ret; |
| 493 | AVCodecContext *c; |
| 494 | AVFrame *frame; |
| 495 | int got_packet = 0; |
| 496 | |
| 497 | c = ost->st->codec; |
| 498 | |
| 499 | frame = get_video_frame(ost); |
| 500 | |
| 501 | if (oc->oformat->flags & AVFMT_RAWPICTURE) { |
| 502 | /* a hack to avoid data copy with some raw video muxers */ |
| 503 | AVPacket pkt; |
| 504 | av_init_packet(&pkt); |
| 505 | |
| 506 | if (!frame) |
| 507 | return 1; |
| 508 | |
| 509 | pkt.flags |= AV_PKT_FLAG_KEY; |
| 510 | pkt.stream_index = ost->st->index; |
| 511 | pkt.data = (uint8_t *)frame; |
| 512 | pkt.size = sizeof(AVPicture); |
| 513 | |
| 514 | pkt.pts = pkt.dts = frame->pts; |
| 515 | av_packet_rescale_ts(&pkt, c->time_base, ost->st->time_base); |
| 516 | |
| 517 | ret = av_interleaved_write_frame(oc, &pkt); |
| 518 | } else { |
| 519 | AVPacket pkt = { 0 }; |
| 520 | av_init_packet(&pkt); |
| 521 | |
| 522 | /* encode the image */ |
| 523 | ret = avcodec_encode_video2(c, &pkt, frame, &got_packet); |
| 524 | if (ret < 0) { |
| 525 | fprintf(stderr, "Error encoding video frame: %s\n", av_err2str(ret)); |
| 526 | exit(1); |
| 527 | } |
| 528 | |
| 529 | if (got_packet) { |
| 530 | ret = write_frame(oc, &c->time_base, ost->st, &pkt); |
| 531 | } else { |
| 532 | ret = 0; |
| 533 | } |
| 534 | } |
| 535 | |
| 536 | if (ret < 0) { |
| 537 | fprintf(stderr, "Error while writing video frame: %s\n", av_err2str(ret)); |
| 538 | exit(1); |
| 539 | } |
| 540 | |
| 541 | return (frame || got_packet) ? 0 : 1; |
| 542 | } |
| 543 | |
| 544 | static void close_stream(AVFormatContext *oc, OutputStream *ost) |
| 545 | { |
| 546 | avcodec_close(ost->st->codec); |
| 547 | av_frame_free(&ost->frame); |
| 548 | av_frame_free(&ost->tmp_frame); |
| 549 | sws_freeContext(ost->sws_ctx); |
| 550 | swr_free(&ost->swr_ctx); |
| 551 | } |
| 552 | |
| 553 | /**************************************************************/ |
| 554 | /* media file output */ |
| 555 | |
| 556 | int main(int argc, char **argv) |
| 557 | { |
| 558 | OutputStream video_st = { 0 }, audio_st = { 0 }; |
| 559 | const char *filename; |
| 560 | AVOutputFormat *fmt; |
| 561 | AVFormatContext *oc; |
| 562 | AVCodec *audio_codec, *video_codec; |
| 563 | int ret; |
| 564 | int have_video = 0, have_audio = 0; |
| 565 | int encode_video = 0, encode_audio = 0; |
| 566 | AVDictionary *opt = NULL; |
| 567 | |
| 568 | /* Initialize libavcodec, and register all codecs and formats. */ |
| 569 | av_register_all(); |
| 570 | |
| 571 | if (argc < 2) { |
| 572 | printf("usage: %s output_file\n" |
| 573 | "API example program to output a media file with libavformat.\n" |
| 574 | "This program generates a synthetic audio and video stream, encodes and\n" |
| 575 | "muxes them into a file named output_file.\n" |
| 576 | "The output format is automatically guessed according to the file extension.\n" |
| 577 | "Raw images can also be output by using '%%d' in the filename.\n" |
| 578 | "\n", argv[0]); |
| 579 | return 1; |
| 580 | } |
| 581 | |
| 582 | filename = argv[1]; |
| 583 | if (argc > 3 && !strcmp(argv[2], "-flags")) { |
| 584 | av_dict_set(&opt, argv[2]+1, argv[3], 0); |
| 585 | } |
| 586 | |
| 587 | /* allocate the output media context */ |
| 588 | avformat_alloc_output_context2(&oc, NULL, NULL, filename); |
| 589 | if (!oc) { |
| 590 | printf("Could not deduce output format from file extension: using MPEG.\n"); |
| 591 | avformat_alloc_output_context2(&oc, NULL, "mpeg", filename); |
| 592 | } |
| 593 | if (!oc) |
| 594 | return 1; |
| 595 | |
| 596 | fmt = oc->oformat; |
| 597 | |
| 598 | /* Add the audio and video streams using the default format codecs |
| 599 | * and initialize the codecs. */ |
| 600 | if (fmt->video_codec != AV_CODEC_ID_NONE) { |
| 601 | add_stream(&video_st, oc, &video_codec, fmt->video_codec); |
| 602 | have_video = 1; |
| 603 | encode_video = 1; |
| 604 | } |
| 605 | if (fmt->audio_codec != AV_CODEC_ID_NONE) { |
| 606 | add_stream(&audio_st, oc, &audio_codec, fmt->audio_codec); |
| 607 | have_audio = 1; |
| 608 | encode_audio = 1; |
| 609 | } |
| 610 | |
| 611 | /* Now that all the parameters are set, we can open the audio and |
| 612 | * video codecs and allocate the necessary encode buffers. */ |
| 613 | if (have_video) |
| 614 | open_video(oc, video_codec, &video_st, opt); |
| 615 | |
| 616 | if (have_audio) |
| 617 | open_audio(oc, audio_codec, &audio_st, opt); |
| 618 | |
| 619 | av_dump_format(oc, 0, filename, 1); |
| 620 | |
| 621 | /* open the output file, if needed */ |
| 622 | if (!(fmt->flags & AVFMT_NOFILE)) { |
| 623 | ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE); |
| 624 | if (ret < 0) { |
| 625 | fprintf(stderr, "Could not open '%s': %s\n", filename, |
| 626 | av_err2str(ret)); |
| 627 | return 1; |
| 628 | } |
| 629 | } |
| 630 | |
| 631 | /* Write the stream header, if any. */ |
| 632 | ret = avformat_write_header(oc, &opt); |
| 633 | if (ret < 0) { |
| 634 | fprintf(stderr, "Error occurred when opening output file: %s\n", |
| 635 | av_err2str(ret)); |
| 636 | return 1; |
| 637 | } |
| 638 | |
| 639 | while (encode_video || encode_audio) { |
| 640 | /* select the stream to encode */ |
| 641 | if (encode_video && |
| 642 | (!encode_audio || av_compare_ts(video_st.next_pts, video_st.st->codec->time_base, |
| 643 | audio_st.next_pts, audio_st.st->codec->time_base) <= 0)) { |
| 644 | encode_video = !write_video_frame(oc, &video_st); |
| 645 | } else { |
| 646 | encode_audio = !write_audio_frame(oc, &audio_st); |
| 647 | } |
| 648 | } |
| 649 | |
| 650 | /* Write the trailer, if any. The trailer must be written before you |
| 651 | * close the CodecContexts open when you wrote the header; otherwise |
| 652 | * av_write_trailer() may try to use memory that was freed on |
| 653 | * av_codec_close(). */ |
| 654 | av_write_trailer(oc); |
| 655 | |
| 656 | /* Close each codec. */ |
| 657 | if (have_video) |
| 658 | close_stream(oc, &video_st); |
| 659 | if (have_audio) |
| 660 | close_stream(oc, &audio_st); |
| 661 | |
| 662 | if (!(fmt->flags & AVFMT_NOFILE)) |
| 663 | /* Close the output file. */ |
| 664 | avio_close(oc->pb); |
| 665 | |
| 666 | /* free the stream */ |
| 667 | avformat_free_context(oc); |
| 668 | |
| 669 | return 0; |
| 670 | } |