14 Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, const string &video_extradata, const AVCodecContext *audio_ctx, int time_base, KeyFrameSignalReceiver *keyframe_signal_receiver)
15 : avctx(avctx), keyframe_signal_receiver(keyframe_signal_receiver)
17 AVCodec *codec_video = avcodec_find_encoder((video_codec == CODEC_H264) ? AV_CODEC_ID_H264 : AV_CODEC_ID_RAWVIDEO);
18 avstream_video = avformat_new_stream(avctx, codec_video);
19 if (avstream_video == nullptr) {
20 fprintf(stderr, "avformat_new_stream() failed\n");
23 avstream_video->time_base = AVRational{1, time_base};
24 avstream_video->codec->codec_type = AVMEDIA_TYPE_VIDEO;
25 if (video_codec == CODEC_H264) {
26 avstream_video->codec->codec_id = AV_CODEC_ID_H264;
28 assert(video_codec == CODEC_NV12);
29 avstream_video->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
30 avstream_video->codec->codec_tag = avcodec_pix_fmt_to_codec_tag(AV_PIX_FMT_NV12);
32 avstream_video->codec->width = width;
33 avstream_video->codec->height = height;
34 avstream_video->codec->time_base = AVRational{1, time_base};
35 avstream_video->codec->ticks_per_frame = 1; // or 2?
37 // Colorspace details. Closely correspond to settings in EffectChain_finalize,
38 // as noted in each comment.
39 // Note that the H.264 stream also contains this information and depending on the
40 // mux, this might simply get ignored. See sps_rbsp().
41 avstream_video->codec->color_primaries = AVCOL_PRI_BT709; // RGB colorspace (inout_format.color_space).
42 avstream_video->codec->color_trc = AVCOL_TRC_UNSPECIFIED; // Gamma curve (inout_format.gamma_curve).
43 avstream_video->codec->colorspace = AVCOL_SPC_SMPTE170M; // YUV colorspace (output_ycbcr_format.luma_coefficients).
44 avstream_video->codec->color_range = AVCOL_RANGE_MPEG; // Full vs. limited range (output_ycbcr_format.full_range).
45 avstream_video->codec->chroma_sample_location = AVCHROMA_LOC_LEFT; // Chroma sample location. See chroma_offset_0[] in Mixer::subsample_chroma().
46 avstream_video->codec->field_order = AV_FIELD_PROGRESSIVE;
48 if (!video_extradata.empty()) {
49 avstream_video->codec->extradata = (uint8_t *)av_malloc(video_extradata.size());
50 avstream_video->codec->extradata_size = video_extradata.size();
51 memcpy(avstream_video->codec->extradata, video_extradata.data(), video_extradata.size());
54 avstream_audio = avformat_new_stream(avctx, nullptr);
55 if (avstream_audio == nullptr) {
56 fprintf(stderr, "avformat_new_stream() failed\n");
59 avstream_audio->time_base = AVRational{1, time_base};
60 avcodec_copy_context(avstream_audio->codec, audio_ctx);
62 AVDictionary *options = NULL;
63 vector<pair<string, string>> opts = MUX_OPTS;
64 for (pair<string, string> opt : opts) {
65 av_dict_set(&options, opt.first.c_str(), opt.second.c_str(), 0);
67 if (avformat_write_header(avctx, &options) < 0) {
68 fprintf(stderr, "avformat_write_header() failed\n");
72 // Make sure the header is written before the constructor exits.
73 avio_flush(avctx->pb);
78 av_write_trailer(avctx);
79 av_free(avctx->pb->buffer);
81 avformat_free_context(avctx);
84 void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts)
87 if (av_copy_packet(&pkt_copy, &pkt) < 0) {
88 fprintf(stderr, "av_copy_packet() failed\n");
91 if (pkt.stream_index == 0) {
92 pkt_copy.pts = av_rescale_q(pts, AVRational{1, TIMEBASE}, avstream_video->time_base);
93 pkt_copy.dts = av_rescale_q(dts, AVRational{1, TIMEBASE}, avstream_video->time_base);
94 pkt_copy.duration = av_rescale_q(pkt.duration, AVRational{1, TIMEBASE}, avstream_video->time_base);
95 } else if (pkt.stream_index == 1) {
96 pkt_copy.pts = av_rescale_q(pts, AVRational{1, TIMEBASE}, avstream_audio->time_base);
97 pkt_copy.dts = av_rescale_q(dts, AVRational{1, TIMEBASE}, avstream_audio->time_base);
98 pkt_copy.duration = av_rescale_q(pkt.duration, AVRational{1, TIMEBASE}, avstream_audio->time_base);
103 if (keyframe_signal_receiver) {
104 if (pkt.flags & AV_PKT_FLAG_KEY) {
105 av_write_frame(avctx, nullptr);
106 keyframe_signal_receiver->signal_keyframe();
111 lock_guard<mutex> lock(mu);
112 if (plug_count > 0) {
113 plugged_packets.push_back(av_packet_clone(&pkt_copy));
114 } else if (av_interleaved_write_frame(avctx, &pkt_copy) < 0) {
115 fprintf(stderr, "av_interleaved_write_frame() failed\n");
120 av_packet_unref(&pkt_copy);
125 lock_guard<mutex> lock(mu);
131 lock_guard<mutex> lock(mu);
132 if (--plug_count > 0) {
135 assert(plug_count >= 0);
137 sort(plugged_packets.begin(), plugged_packets.end(), [](const AVPacket *a, const AVPacket *b) {
138 int64_t a_dts = (a->dts == AV_NOPTS_VALUE ? a->pts : a->dts);
139 int64_t b_dts = (b->dts == AV_NOPTS_VALUE ? b->pts : b->dts);
140 if (a_dts != b_dts) {
141 return a_dts < b_dts;
143 return a->pts < b->pts;
147 for (AVPacket *pkt : plugged_packets) {
148 if (av_interleaved_write_frame(avctx, pkt) < 0) {
149 fprintf(stderr, "av_interleaved_write_frame() failed\n");
152 av_packet_free(&pkt);
154 plugged_packets.clear();