X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=mux.cpp;fp=mux.cpp;h=82d42abe705c75e2af79259252a68e5494e6763f;hb=410a5fadcba336c918843cd55e1516cf4fe56abc;hp=0000000000000000000000000000000000000000;hpb=d8795d38bc8d11ddbbb10037b653f3748aea35a6;p=nageru

diff --git a/mux.cpp b/mux.cpp
new file mode 100644
index 0000000..82d42ab
--- /dev/null
+++ b/mux.cpp
@@ -0,0 +1,115 @@
+#include <assert.h>
+
+#include <string>
+#include <vector>
+
+#include "defs.h"
+#include "mux.h"
+#include "timebase.h"
+
+using namespace std;
+
+Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, int time_base)
+	: avctx(avctx)
+{
+	AVCodec *codec_video = avcodec_find_encoder((video_codec == CODEC_H264) ? AV_CODEC_ID_H264 : AV_CODEC_ID_RAWVIDEO);
+	avstream_video = avformat_new_stream(avctx, codec_video);
+	if (avstream_video == nullptr) {
+		fprintf(stderr, "avformat_new_stream() failed\n");
+		exit(1);
+	}
+	avstream_video->time_base = AVRational{1, time_base};
+	avstream_video->codec->codec_type = AVMEDIA_TYPE_VIDEO;
+	if (video_codec == CODEC_H264) {
+		avstream_video->codec->codec_id = AV_CODEC_ID_H264;
+	} else {
+		assert(video_codec == CODEC_NV12);
+		avstream_video->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
+		avstream_video->codec->codec_tag = avcodec_pix_fmt_to_codec_tag(AV_PIX_FMT_NV12);
+	}
+	avstream_video->codec->width = width;
+	avstream_video->codec->height = height;
+	avstream_video->codec->time_base = AVRational{1, time_base};
+	avstream_video->codec->ticks_per_frame = 1;  // or 2?
+
+	// Colorspace details. Closely correspond to settings in EffectChain_finalize,
+	// as noted in each comment.
+	// Note that the H.264 stream also contains this information and depending on the
+	// mux, this might simply get ignored. See sps_rbsp().
+	avstream_video->codec->color_primaries = AVCOL_PRI_BT709;  // RGB colorspace (inout_format.color_space).
+	avstream_video->codec->color_trc = AVCOL_TRC_UNSPECIFIED;  // Gamma curve (inout_format.gamma_curve).
+	avstream_video->codec->colorspace = AVCOL_SPC_SMPTE170M;  // YUV colorspace (output_ycbcr_format.luma_coefficients).
+	avstream_video->codec->color_range = AVCOL_RANGE_MPEG;  // Full vs. limited range (output_ycbcr_format.full_range).
+	avstream_video->codec->chroma_sample_location = AVCHROMA_LOC_LEFT;  // Chroma sample location. See chroma_offset_0[] in Mixer::subsample_chroma().
+	avstream_video->codec->field_order = AV_FIELD_PROGRESSIVE;
+	if (avctx->oformat->flags & AVFMT_GLOBALHEADER) {
+		avstream_video->codec->flags = AV_CODEC_FLAG_GLOBAL_HEADER;
+	}
+
+	AVCodec *codec_audio = avcodec_find_encoder_by_name(AUDIO_OUTPUT_CODEC_NAME);
+	if (codec_audio == nullptr) {
+		fprintf(stderr, "ERROR: Could not find codec '%s'\n", AUDIO_OUTPUT_CODEC_NAME);
+		exit(1);
+	}
+	avstream_audio = avformat_new_stream(avctx, codec_audio);
+	if (avstream_audio == nullptr) {
+		fprintf(stderr, "avformat_new_stream() failed\n");
+		exit(1);
+	}
+	avstream_audio->time_base = AVRational{1, time_base};
+	avstream_audio->codec->bit_rate = AUDIO_OUTPUT_BIT_RATE;
+	avstream_audio->codec->sample_rate = OUTPUT_FREQUENCY;
+	avstream_audio->codec->channels = 2;
+	avstream_audio->codec->channel_layout = AV_CH_LAYOUT_STEREO;
+	avstream_audio->codec->time_base = AVRational{1, time_base};
+	if (avctx->oformat->flags & AVFMT_GLOBALHEADER) {
+		avstream_audio->codec->flags = AV_CODEC_FLAG_GLOBAL_HEADER;
+	}
+
+	AVDictionary *options = NULL;
+	vector<pair<string, string>> opts = MUX_OPTS;
+	for (pair<string, string> opt : opts) {
+		av_dict_set(&options, opt.first.c_str(), opt.second.c_str(), 0);
+	}
+	if (avformat_write_header(avctx, &options) < 0) {
+		fprintf(stderr, "avformat_write_header() failed\n");
+		exit(1);
+	}
+}
+
+Mux::~Mux()
+{
+	av_write_trailer(avctx);
+	av_free(avctx->pb->buffer);
+	av_free(avctx->pb);
+	avformat_free_context(avctx);
+}
+
+void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts)
+{
+	if (!seen_keyframe && !(pkt.stream_index == 0 && (pkt.flags & AV_PKT_FLAG_KEY))) {
+		// Wait until we see the first (video) key frame.
+		return;
+	}
+	seen_keyframe = true;
+
+	AVPacket pkt_copy;
+	av_copy_packet(&pkt_copy, &pkt);
+	if (pkt.stream_index == 0) {
+		pkt_copy.pts = av_rescale_q(pts, AVRational{1, TIMEBASE}, avstream_video->time_base);
+		pkt_copy.dts = av_rescale_q(dts, AVRational{1, TIMEBASE}, avstream_video->time_base);
+	} else if (pkt.stream_index == 1) {
+		pkt_copy.pts = av_rescale_q(pts, AVRational{1, TIMEBASE}, avstream_audio->time_base);
+		pkt_copy.dts = av_rescale_q(dts, AVRational{1, TIMEBASE}, avstream_audio->time_base);
+	} else {
+		assert(false);
+	}
+
+	if (av_interleaved_write_frame(avctx, &pkt_copy) < 0) {
+		fprintf(stderr, "av_interleaved_write_frame() failed\n");
+		exit(1);
+	}
+
+	av_packet_unref(&pkt_copy);
+}
+