1 // Kaeru (換える), a simple transcoder intended for use with Nageru.
2 // This is experimental code, not yet supported.
4 #include "audio_encoder.h"
7 #include "ffmpeg_capture.h"
11 #include "x264_encoder.h"
19 using namespace bmusb;
20 using namespace movit;
22 using namespace std::placeholders;
24 Mixer *global_mixer = nullptr;
25 X264Encoder *global_x264_encoder = nullptr;
26 MuxMetrics stream_mux_metrics;
28 int write_packet(void *opaque, uint8_t *buf, int buf_size, AVIODataMarkerType type, int64_t time)
30 static bool seen_sync_markers = false;
31 static string stream_mux_header;
32 HTTPD *httpd = (HTTPD *)opaque;
34 if (type == AVIO_DATA_MARKER_SYNC_POINT || type == AVIO_DATA_MARKER_BOUNDARY_POINT) {
35 seen_sync_markers = true;
36 } else if (type == AVIO_DATA_MARKER_UNKNOWN && !seen_sync_markers) {
37 // We don't know if this is a keyframe or not (the muxer could
38 // avoid marking it), so we just have to make the best of it.
39 type = AVIO_DATA_MARKER_SYNC_POINT;
42 if (type == AVIO_DATA_MARKER_HEADER) {
43 stream_mux_header.append((char *)buf, buf_size);
44 httpd->set_header(stream_mux_header);
46 httpd->add_data((char *)buf, buf_size, type == AVIO_DATA_MARKER_SYNC_POINT);
51 unique_ptr<Mux> create_mux(HTTPD *httpd, AVOutputFormat *oformat, X264Encoder *x264_encoder, AudioEncoder *audio_encoder)
53 AVFormatContext *avctx = avformat_alloc_context();
54 avctx->oformat = oformat;
56 uint8_t *buf = (uint8_t *)av_malloc(MUX_BUFFER_SIZE);
57 avctx->pb = avio_alloc_context(buf, MUX_BUFFER_SIZE, 1, httpd, nullptr, nullptr, nullptr);
58 avctx->pb->write_data_type = &write_packet;
59 avctx->pb->ignore_boundary_point = 1;
61 string video_extradata = x264_encoder->get_global_headers();
64 int time_base = global_flags.stream_coarse_timebase ? COARSE_TIMEBASE : TIMEBASE;
65 mux.reset(new Mux(avctx, global_flags.width, global_flags.height, Mux::CODEC_H264, video_extradata, audio_encoder->get_codec_parameters().get(), time_base,
66 /*write_callback=*/nullptr, Mux::WRITE_FOREGROUND, { &stream_mux_metrics }));
67 stream_mux_metrics.init({{ "destination", "http" }});
71 void video_frame_callback(FFmpegCapture *video, X264Encoder *x264_encoder, AudioEncoder *audio_encoder,
72 int64_t video_pts, AVRational video_timebase,
73 int64_t audio_pts, AVRational audio_timebase,
75 FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
76 FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format)
78 if (video_pts >= 0 && video_frame.len > 0) {
79 video_pts = av_rescale_q(video_pts, video_timebase, AVRational{ 1, TIMEBASE });
80 int64_t frame_duration = TIMEBASE * video_format.frame_rate_nom / video_format.frame_rate_den;
81 x264_encoder->add_frame(video_pts, frame_duration, video->get_current_frame_ycbcr_format().luma_coefficients, video_frame.data + video_offset, ReceivedTimestamps());
83 if (audio_frame.len > 0) {
84 // FFmpegCapture takes care of this for us.
85 assert(audio_format.num_channels == 2);
86 assert(audio_format.sample_rate == OUTPUT_FREQUENCY);
88 // TODO: Reduce some duplication against AudioMixer here.
89 size_t num_samples = audio_frame.len / (audio_format.bits_per_sample / 8);
90 vector<float> float_samples;
91 float_samples.resize(num_samples);
92 if (audio_format.bits_per_sample == 16) {
93 const int16_t *src = (const int16_t *)audio_frame.data;
94 float *dst = &float_samples[0];
95 for (size_t i = 0; i < num_samples; ++i) {
96 *dst++ = le16toh(*src++) * (1.0f / 32768.0f);
98 } else if (audio_format.bits_per_sample == 32) {
99 const int32_t *src = (const int32_t *)audio_frame.data;
100 float *dst = &float_samples[0];
101 for (size_t i = 0; i < num_samples; ++i) {
102 *dst++ = le32toh(*src++) * (1.0f / 2147483648.0f);
107 audio_pts = av_rescale_q(audio_pts, audio_timebase, AVRational{ 1, TIMEBASE });
108 audio_encoder->encode_audio(float_samples, audio_pts);
111 if (video_frame.owner) {
112 video_frame.owner->release_frame(video_frame);
114 if (audio_frame.owner) {
115 audio_frame.owner->release_frame(audio_frame);
119 void audio_frame_callback(Mux *mux, const AVPacket *pkt, AVRational timebase)
121 mux->add_packet(*pkt, pkt->pts, pkt->dts == AV_NOPTS_VALUE ? pkt->pts : pkt->dts, timebase);
124 void adjust_bitrate(int signal)
126 int new_bitrate = global_flags.x264_bitrate;
127 if (signal == SIGUSR1) {
129 if (new_bitrate > 100000) {
130 fprintf(stderr, "Ignoring SIGUSR1, can't increase bitrate below 100000 kbit/sec (currently at %d kbit/sec)\n",
131 global_flags.x264_bitrate);
133 fprintf(stderr, "Increasing bitrate to %d kbit/sec due to SIGUSR1.\n", new_bitrate);
134 global_flags.x264_bitrate = new_bitrate;
135 global_x264_encoder->change_bitrate(new_bitrate);
137 } else if (signal == SIGUSR2) {
139 if (new_bitrate < 100) {
140 fprintf(stderr, "Ignoring SIGUSR1, can't decrease bitrate below 100 kbit/sec (currently at %d kbit/sec)\n",
141 global_flags.x264_bitrate);
143 fprintf(stderr, "Decreasing bitrate to %d kbit/sec due to SIGUSR1.\n", new_bitrate);
144 global_flags.x264_bitrate = new_bitrate;
145 global_x264_encoder->change_bitrate(new_bitrate);
150 int main(int argc, char *argv[])
152 parse_flags(PROGRAM_KAERU, argc, argv);
153 if (optind + 1 != argc) {
154 usage(PROGRAM_KAERU);
159 avformat_network_init();
163 AVOutputFormat *oformat = av_guess_format(global_flags.stream_mux_name.c_str(), nullptr, nullptr);
164 assert(oformat != nullptr);
166 unique_ptr<AudioEncoder> audio_encoder;
167 if (global_flags.transcode_audio) {
168 if (global_flags.stream_audio_codec_name.empty()) {
169 audio_encoder.reset(new AudioEncoder(AUDIO_OUTPUT_CODEC_NAME, DEFAULT_AUDIO_OUTPUT_BIT_RATE, oformat));
171 audio_encoder.reset(new AudioEncoder(global_flags.stream_audio_codec_name, global_flags.stream_audio_codec_bitrate, oformat));
175 X264Encoder x264_encoder(oformat);
176 unique_ptr<Mux> http_mux = create_mux(&httpd, oformat, &x264_encoder, audio_encoder.get());
177 if (global_flags.transcode_audio) {
178 audio_encoder->add_mux(http_mux.get());
180 x264_encoder.add_mux(http_mux.get());
181 global_x264_encoder = &x264_encoder;
183 FFmpegCapture video(argv[optind], global_flags.width, global_flags.height);
184 video.set_pixel_format(FFmpegCapture::PixelFormat_NV12);
185 video.set_frame_callback(bind(video_frame_callback, &video, &x264_encoder, audio_encoder.get(), _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11));
186 if (!global_flags.transcode_audio) {
187 video.set_audio_callback(bind(audio_frame_callback, http_mux.get(), _1, _2));
189 video.configure_card();
190 video.start_bm_capture();
191 video.change_rate(2.0); // Be sure never to really fall behind, but also don't dump huge amounts of stuff onto x264.
195 signal(SIGUSR1, adjust_bitrate);
196 signal(SIGUSR2, adjust_bitrate);