/* * Copyright (c) 2003 Fabrice Bellard * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ /** * @file * libavformat API example. * * Output a media file in any supported libavformat format. * The default codecs are used. * @example doc/examples/muxing.c */ #include #include #include #include #include #include #include #include #include /* 5 seconds stream duration */ #define STREAM_DURATION 200.0 #define STREAM_FRAME_RATE 25 /* 25 images/s */ #define STREAM_NB_FRAMES ((int)(STREAM_DURATION * STREAM_FRAME_RATE)) #define STREAM_PIX_FMT AV_PIX_FMT_YUV420P /* default pix_fmt */ static int sws_flags = SWS_BICUBIC; /* Add an output stream. */ static AVStream *add_stream(AVFormatContext *oc, AVCodec **codec, enum AVCodecID codec_id) { AVCodecContext *c; AVStream *st; /* find the encoder */ *codec = avcodec_find_encoder(codec_id); if (!(*codec)) { fprintf(stderr, "Could not find encoder for '%s'\n", avcodec_get_name(codec_id)); exit(1); } st = avformat_new_stream(oc, *codec); if (!st) { fprintf(stderr, "Could not allocate stream\n"); exit(1); } st->id = oc->nb_streams-1; c = st->codec; switch ((*codec)->type) { case AVMEDIA_TYPE_AUDIO: c->sample_fmt = (*codec)->sample_fmts ? (*codec)->sample_fmts[0] : AV_SAMPLE_FMT_FLTP; c->bit_rate = 64000; c->sample_rate = 44100; c->channels = 2; break; case AVMEDIA_TYPE_VIDEO: c->codec_id = codec_id; c->bit_rate = 400000; /* Resolution must be a multiple of two. */ c->width = 352; c->height = 288; /* timebase: This is the fundamental unit of time (in seconds) in terms * of which frame timestamps are represented. For fixed-fps content, * timebase should be 1/framerate and timestamp increments should be * identical to 1. */ c->time_base.den = STREAM_FRAME_RATE; c->time_base.num = 1; c->gop_size = 12; /* emit one intra frame every twelve frames at most */ c->pix_fmt = STREAM_PIX_FMT; if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) { /* just for testing, we also add B frames */ c->max_b_frames = 2; } if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) { /* Needed to avoid using macroblocks in which some coeffs overflow. * This does not happen with normal video, it just happens here as * the motion of the chroma plane does not match the luma plane. */ c->mb_decision = 2; } break; default: break; } /* Some formats want stream headers to be separate. */ if (oc->oformat->flags & AVFMT_GLOBALHEADER) c->flags |= CODEC_FLAG_GLOBAL_HEADER; return st; } /**************************************************************/ /* audio output */ static float t, tincr, tincr2; AVFrame *audio_frame; static uint8_t **src_samples_data; static int src_samples_linesize; static int src_nb_samples; static int max_dst_nb_samples; uint8_t **dst_samples_data; int dst_samples_linesize; int dst_samples_size; int samples_count; struct SwrContext *swr_ctx = NULL; static void open_audio(AVFormatContext *oc, AVCodec *codec, AVStream *st) { AVCodecContext *c; int ret; c = st->codec; /* allocate and init a re-usable frame */ audio_frame = av_frame_alloc(); if (!audio_frame) { fprintf(stderr, "Could not allocate audio frame\n"); exit(1); } /* open it */ ret = avcodec_open2(c, codec, NULL); if (ret < 0) { fprintf(stderr, "Could not open audio codec: %s\n", av_err2str(ret)); exit(1); } /* init signal generator */ t = 0; tincr = 2 * M_PI * 110.0 / c->sample_rate; /* increment frequency by 110 Hz per second */ tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate; src_nb_samples = c->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE ? 10000 : c->frame_size; ret = av_samples_alloc_array_and_samples(&src_samples_data, &src_samples_linesize, c->channels, src_nb_samples, AV_SAMPLE_FMT_S16, 0); if (ret < 0) { fprintf(stderr, "Could not allocate source samples\n"); exit(1); } /* compute the number of converted samples: buffering is avoided * ensuring that the output buffer will contain at least all the * converted input samples */ max_dst_nb_samples = src_nb_samples; /* create resampler context */ if (c->sample_fmt != AV_SAMPLE_FMT_S16) { swr_ctx = swr_alloc(); if (!swr_ctx) { fprintf(stderr, "Could not allocate resampler context\n"); exit(1); } /* set options */ av_opt_set_int (swr_ctx, "in_channel_count", c->channels, 0); av_opt_set_int (swr_ctx, "in_sample_rate", c->sample_rate, 0); av_opt_set_sample_fmt(swr_ctx, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0); av_opt_set_int (swr_ctx, "out_channel_count", c->channels, 0); av_opt_set_int (swr_ctx, "out_sample_rate", c->sample_rate, 0); av_opt_set_sample_fmt(swr_ctx, "out_sample_fmt", c->sample_fmt, 0); /* initialize the resampling context */ if ((ret = swr_init(swr_ctx)) < 0) { fprintf(stderr, "Failed to initialize the resampling context\n"); exit(1); } ret = av_samples_alloc_array_and_samples(&dst_samples_data, &dst_samples_linesize, c->channels, max_dst_nb_samples, c->sample_fmt, 0); if (ret < 0) { fprintf(stderr, "Could not allocate destination samples\n"); exit(1); } } else { dst_samples_data = src_samples_data; } dst_samples_size = av_samples_get_buffer_size(NULL, c->channels, max_dst_nb_samples, c->sample_fmt, 0); } /* Prepare a 16 bit dummy audio frame of 'frame_size' samples and * 'nb_channels' channels. */ static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels) { int j, i, v; int16_t *q; q = samples; for (j = 0; j < frame_size; j++) { v = (int)(sin(t) * 10000); for (i = 0; i < nb_channels; i++) *q++ = v; t += tincr; tincr += tincr2; } } static void write_audio_frame(AVFormatContext *oc, AVStream *st) { AVCodecContext *c; AVPacket pkt = { 0 }; // data and size must be 0; int got_packet, ret, dst_nb_samples; av_init_packet(&pkt); c = st->codec; get_audio_frame((int16_t *)src_samples_data[0], src_nb_samples, c->channels); /* convert samples from native format to destination codec format, using the resampler */ if (swr_ctx) { /* compute destination number of samples */ dst_nb_samples = av_rescale_rnd(swr_get_delay(swr_ctx, c->sample_rate) + src_nb_samples, c->sample_rate, c->sample_rate, AV_ROUND_UP); if (dst_nb_samples > max_dst_nb_samples) { av_free(dst_samples_data[0]); ret = av_samples_alloc(dst_samples_data, &dst_samples_linesize, c->channels, dst_nb_samples, c->sample_fmt, 0); if (ret < 0) exit(1); max_dst_nb_samples = dst_nb_samples; dst_samples_size = av_samples_get_buffer_size(NULL, c->channels, dst_nb_samples, c->sample_fmt, 0); } /* convert to destination format */ ret = swr_convert(swr_ctx, dst_samples_data, dst_nb_samples, (const uint8_t **)src_samples_data, src_nb_samples); if (ret < 0) { fprintf(stderr, "Error while converting\n"); exit(1); } } else { dst_nb_samples = src_nb_samples; } audio_frame->nb_samples = dst_nb_samples; audio_frame->pts = av_rescale_q(samples_count, (AVRational){1, c->sample_rate}, c->time_base); avcodec_fill_audio_frame(audio_frame, c->channels, c->sample_fmt, dst_samples_data[0], dst_samples_size, 0); samples_count += dst_nb_samples; ret = avcodec_encode_audio2(c, &pkt, audio_frame, &got_packet); if (ret < 0) { fprintf(stderr, "Error encoding audio frame: %s\n", av_err2str(ret)); exit(1); } if (!got_packet) return; /* rescale output packet timestamp values from codec to stream timebase */ pkt.pts = av_rescale_q_rnd(pkt.pts, c->time_base, st->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX); pkt.dts = av_rescale_q_rnd(pkt.dts, c->time_base, st->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX); pkt.duration = av_rescale_q(pkt.duration, c->time_base, st->time_base); pkt.stream_index = st->index; /* Write the compressed frame to the media file. */ ret = av_interleaved_write_frame(oc, &pkt); if (ret != 0) { fprintf(stderr, "Error while writing audio frame: %s\n", av_err2str(ret)); exit(1); } } static void close_audio(AVFormatContext *oc, AVStream *st) { avcodec_close(st->codec); if (dst_samples_data != src_samples_data) { av_free(dst_samples_data[0]); av_free(dst_samples_data); } av_free(src_samples_data[0]); av_free(src_samples_data); av_frame_free(&audio_frame); } /**************************************************************/ /* video output */ static AVFrame *frame; static AVPicture src_picture, dst_picture; static int frame_count; static void open_video(AVFormatContext *oc, AVCodec *codec, AVStream *st) { int ret; AVCodecContext *c = st->codec; /* open the codec */ ret = avcodec_open2(c, codec, NULL); if (ret < 0) { fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret)); exit(1); } /* allocate and init a re-usable frame */ frame = av_frame_alloc(); if (!frame) { fprintf(stderr, "Could not allocate video frame\n"); exit(1); } frame->format = c->pix_fmt; frame->width = c->width; frame->height = c->height; /* Allocate the encoded raw picture. */ ret = avpicture_alloc(&dst_picture, c->pix_fmt, c->width, c->height); if (ret < 0) { fprintf(stderr, "Could not allocate picture: %s\n", av_err2str(ret)); exit(1); } /* If the output format is not YUV420P, then a temporary YUV420P * picture is needed too. It is then converted to the required * output format. */ if (c->pix_fmt != AV_PIX_FMT_YUV420P) { ret = avpicture_alloc(&src_picture, AV_PIX_FMT_YUV420P, c->width, c->height); if (ret < 0) { fprintf(stderr, "Could not allocate temporary picture: %s\n", av_err2str(ret)); exit(1); } } /* copy data and linesize picture pointers to frame */ *((AVPicture *)frame) = dst_picture; } /* Prepare a dummy image. */ static void fill_yuv_image(AVPicture *pict, int frame_index, int width, int height) { int x, y, i; i = frame_index; /* Y */ for (y = 0; y < height; y++) for (x = 0; x < width; x++) pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3; /* Cb and Cr */ for (y = 0; y < height / 2; y++) { for (x = 0; x < width / 2; x++) { pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2; pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5; } } } static void write_video_frame(AVFormatContext *oc, AVStream *st) { int ret; static struct SwsContext *sws_ctx; AVCodecContext *c = st->codec; if (frame_count >= STREAM_NB_FRAMES) { /* No more frames to compress. The codec has a latency of a few * frames if using B-frames, so we get the last frames by * passing the same picture again. */ } else { if (c->pix_fmt != AV_PIX_FMT_YUV420P) { /* as we only generate a YUV420P picture, we must convert it * to the codec pixel format if needed */ if (!sws_ctx) { sws_ctx = sws_getContext(c->width, c->height, AV_PIX_FMT_YUV420P, c->width, c->height, c->pix_fmt, sws_flags, NULL, NULL, NULL); if (!sws_ctx) { fprintf(stderr, "Could not initialize the conversion context\n"); exit(1); } } fill_yuv_image(&src_picture, frame_count, c->width, c->height); sws_scale(sws_ctx, (const uint8_t * const *)src_picture.data, src_picture.linesize, 0, c->height, dst_picture.data, dst_picture.linesize); } else { fill_yuv_image(&dst_picture, frame_count, c->width, c->height); } } if (oc->oformat->flags & AVFMT_RAWPICTURE) { /* Raw video case - directly store the picture in the packet */ AVPacket pkt; av_init_packet(&pkt); pkt.flags |= AV_PKT_FLAG_KEY; pkt.stream_index = st->index; pkt.data = dst_picture.data[0]; pkt.size = sizeof(AVPicture); ret = av_interleaved_write_frame(oc, &pkt); } else { AVPacket pkt = { 0 }; int got_packet; av_init_packet(&pkt); /* encode the image */ frame->pts = frame_count; ret = avcodec_encode_video2(c, &pkt, frame, &got_packet); if (ret < 0) { fprintf(stderr, "Error encoding video frame: %s\n", av_err2str(ret)); exit(1); } /* If size is zero, it means the image was buffered. */ if (!ret && got_packet && pkt.size) { /* rescale output packet timestamp values from codec to stream timebase */ pkt.pts = av_rescale_q_rnd(pkt.pts, c->time_base, st->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX); pkt.dts = av_rescale_q_rnd(pkt.dts, c->time_base, st->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX); pkt.duration = av_rescale_q(pkt.duration, c->time_base, st->time_base); pkt.stream_index = st->index; /* Write the compressed frame to the media file. */ ret = av_interleaved_write_frame(oc, &pkt); } else { ret = 0; } } if (ret != 0) { fprintf(stderr, "Error while writing video frame: %s\n", av_err2str(ret)); exit(1); } frame_count++; } static void close_video(AVFormatContext *oc, AVStream *st) { avcodec_close(st->codec); av_free(src_picture.data[0]); av_free(dst_picture.data[0]); av_frame_free(&frame); } /**************************************************************/ /* media file output */ int main(int argc, char **argv) { const char *filename; AVOutputFormat *fmt; AVFormatContext *oc; AVStream *audio_st, *video_st; AVCodec *audio_codec, *video_codec; double audio_time, video_time; int ret; /* Initialize libavcodec, and register all codecs and formats. */ av_register_all(); if (argc != 2) { printf("usage: %s output_file\n" "API example program to output a media file with libavformat.\n" "This program generates a synthetic audio and video stream, encodes and\n" "muxes them into a file named output_file.\n" "The output format is automatically guessed according to the file extension.\n" "Raw images can also be output by using '%%d' in the filename.\n" "\n", argv[0]); return 1; } filename = argv[1]; /* allocate the output media context */ avformat_alloc_output_context2(&oc, NULL, NULL, filename); if (!oc) { printf("Could not deduce output format from file extension: using MPEG.\n"); avformat_alloc_output_context2(&oc, NULL, "mpeg", filename); } if (!oc) { return 1; } fmt = oc->oformat; /* Add the audio and video streams using the default format codecs * and initialize the codecs. */ video_st = NULL; audio_st = NULL; if (fmt->video_codec != AV_CODEC_ID_NONE) { video_st = add_stream(oc, &video_codec, fmt->video_codec); } if (fmt->audio_codec != AV_CODEC_ID_NONE) { audio_st = add_stream(oc, &audio_codec, fmt->audio_codec); } /* Now that all the parameters are set, we can open the audio and * video codecs and allocate the necessary encode buffers. */ if (video_st) open_video(oc, video_codec, video_st); if (audio_st) open_audio(oc, audio_codec, audio_st); av_dump_format(oc, 0, filename, 1); /* open the output file, if needed */ if (!(fmt->flags & AVFMT_NOFILE)) { ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE); if (ret < 0) { fprintf(stderr, "Could not open '%s': %s\n", filename, av_err2str(ret)); return 1; } } /* Write the stream header, if any. */ ret = avformat_write_header(oc, NULL); if (ret < 0) { fprintf(stderr, "Error occurred when opening output file: %s\n", av_err2str(ret)); return 1; } for (;;) { /* Compute current audio and video time. */ audio_time = audio_st ? audio_st->pts.val * av_q2d(audio_st->time_base) : 0.0; video_time = video_st ? video_st->pts.val * av_q2d(video_st->time_base) : 0.0; if ((!audio_st || audio_time >= STREAM_DURATION) && (!video_st || video_time >= STREAM_DURATION)) break; /* write interleaved audio and video frames */ if (!video_st || (video_st && audio_st && audio_time < video_time)) { write_audio_frame(oc, audio_st); } else { write_video_frame(oc, video_st); } } /* Write the trailer, if any. The trailer must be written before you * close the CodecContexts open when you wrote the header; otherwise * av_write_trailer() may try to use memory that was freed on * av_codec_close(). */ av_write_trailer(oc); /* Close each codec. */ if (video_st) close_video(oc, video_st); if (audio_st) close_audio(oc, audio_st); if (!(fmt->flags & AVFMT_NOFILE)) /* Close the output file. */ avio_close(oc->pb); /* free the stream */ avformat_free_context(oc); return 0; }