X-Git-Url: https://git.sesse.net/?p=nageru;a=blobdiff_plain;f=ffmpeg_capture.cpp;h=5f95da240448a5ec90efd45cd9c80b9b1a4dd2e3;hp=5474c52fd94f511491206e4f8a92b2545bc87475;hb=refs%2Fheads%2Fffmpeg-audio-only;hpb=f07adb19f0e2571bf4894ec57e6fcfe4a3e5fd95 diff --git a/ffmpeg_capture.cpp b/ffmpeg_capture.cpp index 5474c52..5f95da2 100644 --- a/ffmpeg_capture.cpp +++ b/ffmpeg_capture.cpp @@ -6,6 +6,7 @@ #include #include #include +#include #include extern "C" { @@ -17,6 +18,7 @@ extern "C" { #include #include #include +#include #include } @@ -27,14 +29,18 @@ extern "C" { #include "bmusb/bmusb.h" #include "ffmpeg_raii.h" +#include "ffmpeg_util.h" #include "flags.h" #include "image_input.h" +#include "ref_counted_frame.h" +#include "timebase.h" #define FRAME_SIZE (8 << 20) // 8 MB. using namespace std; using namespace std::chrono; using namespace bmusb; +using namespace movit; namespace { @@ -44,13 +50,169 @@ steady_clock::time_point compute_frame_start(int64_t frame_pts, int64_t pts_orig return origin + duration_cast(pts / rate); } +bool changed_since(const std::string &pathname, const timespec &ts) +{ + if (ts.tv_sec < 0) { + return false; + } + struct stat buf; + if (stat(pathname.c_str(), &buf) != 0) { + fprintf(stderr, "%s: Couldn't check for new version, leaving the old in place.\n", pathname.c_str()); + return false; + } + return (buf.st_mtim.tv_sec != ts.tv_sec || buf.st_mtim.tv_nsec != ts.tv_nsec); +} + +bool is_full_range(const AVPixFmtDescriptor *desc) +{ + // This is horrible, but there's no better way that I know of. + return (strchr(desc->name, 'j') != nullptr); +} + +AVPixelFormat decide_dst_format(AVPixelFormat src_format, bmusb::PixelFormat dst_format_type) +{ + if (dst_format_type == bmusb::PixelFormat_8BitBGRA) { + return AV_PIX_FMT_BGRA; + } + if (dst_format_type == FFmpegCapture::PixelFormat_NV12) { + return AV_PIX_FMT_NV12; + } + + assert(dst_format_type == bmusb::PixelFormat_8BitYCbCrPlanar); + + // If this is a non-Y'CbCr format, just convert to 4:4:4 Y'CbCr + // and be done with it. It's too strange to spend a lot of time on. + // (Let's hope there's no alpha.) + const AVPixFmtDescriptor *src_desc = av_pix_fmt_desc_get(src_format); + if (src_desc == nullptr || + src_desc->nb_components != 3 || + (src_desc->flags & AV_PIX_FMT_FLAG_RGB)) { + return AV_PIX_FMT_YUV444P; + } + + // The best for us would be Cb and Cr together if possible, + // but FFmpeg doesn't support that except in the special case of + // NV12, so we need to go to planar even for the case of NV12. + // Thus, look for the closest (but no worse) 8-bit planar Y'CbCr format + // that matches in color range. (This will also include the case of + // the source format already being acceptable.) + bool src_full_range = is_full_range(src_desc); + const char *best_format = "yuv444p"; + unsigned best_score = numeric_limits::max(); + for (const AVPixFmtDescriptor *desc = av_pix_fmt_desc_next(nullptr); + desc; + desc = av_pix_fmt_desc_next(desc)) { + // Find planar Y'CbCr formats only. + if (desc->nb_components != 3) continue; + if (desc->flags & AV_PIX_FMT_FLAG_RGB) continue; + if (!(desc->flags & AV_PIX_FMT_FLAG_PLANAR)) continue; + if (desc->comp[0].plane != 0 || + desc->comp[1].plane != 1 || + desc->comp[2].plane != 2) continue; + + // 8-bit formats only. + if (desc->flags & AV_PIX_FMT_FLAG_BE) continue; + if (desc->comp[0].depth != 8) continue; + + // Same or better chroma resolution only. + int chroma_w_diff = desc->log2_chroma_w - src_desc->log2_chroma_w; + int chroma_h_diff = desc->log2_chroma_h - src_desc->log2_chroma_h; + if (chroma_w_diff < 0 || chroma_h_diff < 0) + continue; + + // Matching full/limited range only. + if (is_full_range(desc) != src_full_range) + continue; + + // Pick something with as little excess chroma resolution as possible. + unsigned score = (1 << (chroma_w_diff)) << chroma_h_diff; + if (score < best_score) { + best_score = score; + best_format = desc->name; + } + } + return av_get_pix_fmt(best_format); +} + +YCbCrFormat decode_ycbcr_format(const AVPixFmtDescriptor *desc, const AVFrame *frame) +{ + YCbCrFormat format; + AVColorSpace colorspace = av_frame_get_colorspace(frame); + switch (colorspace) { + case AVCOL_SPC_BT709: + format.luma_coefficients = YCBCR_REC_709; + break; + case AVCOL_SPC_BT470BG: + case AVCOL_SPC_SMPTE170M: + case AVCOL_SPC_SMPTE240M: + format.luma_coefficients = YCBCR_REC_601; + break; + case AVCOL_SPC_BT2020_NCL: + format.luma_coefficients = YCBCR_REC_2020; + break; + case AVCOL_SPC_UNSPECIFIED: + format.luma_coefficients = (frame->height >= 720 ? YCBCR_REC_709 : YCBCR_REC_601); + break; + default: + fprintf(stderr, "Unknown Y'CbCr coefficient enum %d from FFmpeg; choosing Rec. 709.\n", + colorspace); + format.luma_coefficients = YCBCR_REC_709; + break; + } + + format.full_range = is_full_range(desc); + format.num_levels = 1 << desc->comp[0].depth; + format.chroma_subsampling_x = 1 << desc->log2_chroma_w; + format.chroma_subsampling_y = 1 << desc->log2_chroma_h; + + switch (frame->chroma_location) { + case AVCHROMA_LOC_LEFT: + format.cb_x_position = 0.0; + format.cb_y_position = 0.5; + break; + case AVCHROMA_LOC_CENTER: + format.cb_x_position = 0.5; + format.cb_y_position = 0.5; + break; + case AVCHROMA_LOC_TOPLEFT: + format.cb_x_position = 0.0; + format.cb_y_position = 0.0; + break; + case AVCHROMA_LOC_TOP: + format.cb_x_position = 0.5; + format.cb_y_position = 0.0; + break; + case AVCHROMA_LOC_BOTTOMLEFT: + format.cb_x_position = 0.0; + format.cb_y_position = 1.0; + break; + case AVCHROMA_LOC_BOTTOM: + format.cb_x_position = 0.5; + format.cb_y_position = 1.0; + break; + default: + fprintf(stderr, "Unknown chroma location coefficient enum %d from FFmpeg; choosing Rec. 709.\n", + frame->chroma_location); + format.cb_x_position = 0.5; + format.cb_y_position = 0.5; + break; + } + + format.cr_x_position = format.cb_x_position; + format.cr_y_position = format.cb_y_position; + return format; +} + } // namespace FFmpegCapture::FFmpegCapture(const string &filename, unsigned width, unsigned height) - : filename(filename), width(width), height(height) + : filename(filename), width(width), height(height), video_timebase{1, 1} { - // Not really used for anything. description = "Video: " + filename; + + last_frame = steady_clock::now(); + + avformat_network_init(); // In case someone wants this. } FFmpegCapture::~FFmpegCapture() @@ -58,6 +220,7 @@ FFmpegCapture::~FFmpegCapture() if (has_dequeue_callbacks) { dequeue_cleanup_callback(); } + avresample_free(&resampler); } void FFmpegCapture::configure_card() @@ -67,7 +230,8 @@ void FFmpegCapture::configure_card() set_video_frame_allocator(owned_video_frame_allocator.get()); } if (audio_frame_allocator == nullptr) { - owned_audio_frame_allocator.reset(new MallocFrameAllocator(65536, NUM_QUEUED_AUDIO_FRAMES)); + // Audio can come out in pretty large chunks, so increase from the default 1 MB. + owned_audio_frame_allocator.reset(new MallocFrameAllocator(1 << 20, NUM_QUEUED_AUDIO_FRAMES)); set_audio_frame_allocator(owned_audio_frame_allocator.get()); } } @@ -118,15 +282,24 @@ void FFmpegCapture::producer_thread_func() pthread_setname_np(pthread_self(), thread_name); while (!producer_thread_should_quit.should_quit()) { - string pathname = search_for_file(filename); - if (filename.empty()) { - fprintf(stderr, "%s not found, sleeping one second and trying again...\n", filename.c_str()); + string filename_copy; + { + lock_guard lock(filename_mu); + filename_copy = filename; + } + + string pathname = search_for_file(filename_copy); + if (pathname.empty()) { + fprintf(stderr, "%s not found, sleeping one second and trying again...\n", filename_copy.c_str()); + send_disconnected_frame(); producer_thread_should_quit.sleep_for(seconds(1)); continue; } + should_interrupt = false; if (!play_video(pathname)) { // Error. fprintf(stderr, "Error when playing %s, sleeping one second and trying again...\n", pathname.c_str()); + send_disconnected_frame(); producer_thread_should_quit.sleep_for(seconds(1)); continue; } @@ -140,9 +313,62 @@ void FFmpegCapture::producer_thread_func() } } +void FFmpegCapture::send_disconnected_frame() +{ + // Send an empty frame to signal that we have no signal anymore. + FrameAllocator::Frame video_frame = video_frame_allocator->alloc_frame(); + if (video_frame.data) { + VideoFormat video_format; + video_format.width = width; + video_format.height = height; + video_format.frame_rate_nom = 60; + video_format.frame_rate_den = 1; + video_format.is_connected = false; + if (pixel_format == bmusb::PixelFormat_8BitBGRA) { + video_format.stride = width * 4; + video_frame.len = width * height * 4; + memset(video_frame.data, 0, video_frame.len); + } else { + video_format.stride = width; + current_frame_ycbcr_format.luma_coefficients = YCBCR_REC_709; + current_frame_ycbcr_format.full_range = true; + current_frame_ycbcr_format.num_levels = 256; + current_frame_ycbcr_format.chroma_subsampling_x = 2; + current_frame_ycbcr_format.chroma_subsampling_y = 2; + current_frame_ycbcr_format.cb_x_position = 0.0f; + current_frame_ycbcr_format.cb_y_position = 0.0f; + current_frame_ycbcr_format.cr_x_position = 0.0f; + current_frame_ycbcr_format.cr_y_position = 0.0f; + video_frame.len = width * height * 2; + memset(video_frame.data, 0, width * height); + memset(video_frame.data + width * height, 128, width * height); // Valid for both NV12 and planar. + } + + frame_callback(-1, AVRational{1, TIMEBASE}, -1, AVRational{1, TIMEBASE}, timecode++, + video_frame, /*video_offset=*/0, video_format, + FrameAllocator::Frame(), /*audio_offset=*/0, AudioFormat()); + last_frame_was_connected = false; + } +} + bool FFmpegCapture::play_video(const string &pathname) { - auto format_ctx = avformat_open_input_unique(pathname.c_str(), nullptr, nullptr); + // Note: Call before open, not after; otherwise, there's a race. + // (There is now, too, but it tips the correct way. We could use fstat() + // if we had the file descriptor.) + timespec last_modified; + struct stat buf; + if (stat(pathname.c_str(), &buf) != 0) { + // Probably some sort of protocol, so can't stat. + last_modified.tv_sec = -1; + } else { + last_modified = buf.st_mtim; + } + + AVDictionary *opts = nullptr; + av_dict_set(&opts, "fflags", "nobuffer", 0); + + auto format_ctx = avformat_open_input_unique(pathname.c_str(), nullptr, &opts, AVIOInterruptCB{ &FFmpegCapture::interrupt_cb_thunk, this }); if (format_ctx == nullptr) { fprintf(stderr, "%s: Error opening file\n", pathname.c_str()); return false; @@ -153,164 +379,531 @@ bool FFmpegCapture::play_video(const string &pathname) return false; } - int video_stream_index = -1, audio_stream_index = -1; - AVRational video_timebase{ 1, 1 }; - for (unsigned i = 0; i < format_ctx->nb_streams; ++i) { - if (format_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && - video_stream_index == -1) { - video_stream_index = i; - video_timebase = format_ctx->streams[i]->time_base; - } - if (format_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO && - audio_stream_index == -1) { - audio_stream_index = i; - } - } - if (video_stream_index == -1) { - fprintf(stderr, "%s: No video stream found\n", pathname.c_str()); - return false; - } + int video_stream_index = find_stream_index(format_ctx.get(), AVMEDIA_TYPE_VIDEO); + int audio_stream_index = find_stream_index(format_ctx.get(), AVMEDIA_TYPE_AUDIO); - const AVCodecParameters *codecpar = format_ctx->streams[video_stream_index]->codecpar; - AVCodecContextWithDeleter codec_ctx = avcodec_alloc_context3_unique(nullptr); - if (avcodec_parameters_to_context(codec_ctx.get(), codecpar) < 0) { - fprintf(stderr, "%s: Cannot fill codec parameters\n", pathname.c_str()); + if (video_stream_index == -1 && audio_stream_index == -1) { + fprintf(stderr, "%s: No audio nor video stream found\n", pathname.c_str()); return false; } - AVCodec *codec = avcodec_find_decoder(codecpar->codec_id); - if (codec == nullptr) { - fprintf(stderr, "%s: Cannot find decoder\n", pathname.c_str()); - return false; + if (video_stream_index == -1) { + fprintf(stderr, "%s: No video stream found, assuming audio-only.\n", pathname.c_str()); } - if (avcodec_open2(codec_ctx.get(), codec, nullptr) < 0) { - fprintf(stderr, "%s: Cannot open decoder\n", pathname.c_str()); - return false; + const bool audio_only_stream = (video_stream_index == -1); + + // Open video decoder, if we have video. + AVCodecContextWithDeleter video_codec_ctx; + if (video_stream_index != -1) { + const AVCodecParameters *video_codecpar = format_ctx->streams[video_stream_index]->codecpar; + AVCodec *video_codec = avcodec_find_decoder(video_codecpar->codec_id); + video_timebase = format_ctx->streams[video_stream_index]->time_base; + video_codec_ctx = avcodec_alloc_context3_unique(nullptr); + if (avcodec_parameters_to_context(video_codec_ctx.get(), video_codecpar) < 0) { + fprintf(stderr, "%s: Cannot fill video codec parameters\n", pathname.c_str()); + return false; + } + if (video_codec == nullptr) { + fprintf(stderr, "%s: Cannot find video decoder\n", pathname.c_str()); + return false; + } + if (avcodec_open2(video_codec_ctx.get(), video_codec, nullptr) < 0) { + fprintf(stderr, "%s: Cannot open video decoder\n", pathname.c_str()); + return false; + } } - unique_ptr codec_ctx_cleanup( - codec_ctx.get(), avcodec_close); - - int64_t pts_origin = 0, last_pts = 0; - steady_clock::time_point start = steady_clock::now(); - steady_clock::time_point next_frame_start = start; - double rate = 1.0; + unique_ptr video_codec_ctx_cleanup( + video_codec_ctx.get(), avcodec_close); + + // Open audio decoder, if we have audio. + AVCodecContextWithDeleter audio_codec_ctx; + if (audio_stream_index != -1) { + audio_codec_ctx = avcodec_alloc_context3_unique(nullptr); + const AVCodecParameters *audio_codecpar = format_ctx->streams[audio_stream_index]->codecpar; + audio_timebase = format_ctx->streams[audio_stream_index]->time_base; + if (avcodec_parameters_to_context(audio_codec_ctx.get(), audio_codecpar) < 0) { + fprintf(stderr, "%s: Cannot fill audio codec parameters\n", pathname.c_str()); + return false; + } + AVCodec *audio_codec = avcodec_find_decoder(audio_codecpar->codec_id); + if (audio_codec == nullptr) { + fprintf(stderr, "%s: Cannot find audio decoder\n", pathname.c_str()); + return false; + } + if (avcodec_open2(audio_codec_ctx.get(), audio_codec, nullptr) < 0) { + fprintf(stderr, "%s: Cannot open audio decoder\n", pathname.c_str()); + return false; + } + } + unique_ptr audio_codec_ctx_cleanup( + audio_codec_ctx.get(), avcodec_close); - unique_ptr sws_ctx(nullptr, sws_freeContext); - int sws_last_width = -1, sws_last_height = -1; + internal_rewind(); // Main loop. + bool first_frame = true; while (!producer_thread_should_quit.should_quit()) { - // Process any queued commands from other threads. - vector commands; - { - lock_guard lock(queue_mu); - swap(commands, command_queue); + if (process_queued_commands(format_ctx.get(), pathname, last_modified, /*rewound=*/nullptr)) { + return true; + } + UniqueFrame audio_frame = audio_frame_allocator->alloc_frame(); + AudioFormat audio_format; + + int64_t audio_pts; + bool error; + AVFrameWithDeleter frame = decode_frame(format_ctx.get(), video_codec_ctx.get(), audio_codec_ctx.get(), + pathname, video_stream_index, audio_stream_index, audio_frame.get(), &audio_format, &audio_pts, &error); + if (error) { + return false; } - for (const QueuedCommand &cmd : commands) { - switch (cmd.command) { - case QueuedCommand::REWIND: - if (av_seek_frame(format_ctx.get(), /*stream_index=*/-1, /*timestamp=*/0, /*flags=*/0) < 0) { - fprintf(stderr, "%s: Rewind failed, stopping play.\n", pathname.c_str()); + if (frame == nullptr && !(audio_only_stream && audio_frame->len > 0)) { + // EOF. Loop back to the start if we can. + if (av_seek_frame(format_ctx.get(), /*stream_index=*/-1, /*timestamp=*/0, /*flags=*/0) < 0) { + fprintf(stderr, "%s: Rewind failed, not looping.\n", pathname.c_str()); + return true; + } + if (video_codec_ctx != nullptr) { + avcodec_flush_buffers(video_codec_ctx.get()); + } + if (audio_codec_ctx != nullptr) { + avcodec_flush_buffers(audio_codec_ctx.get()); + } + // If the file has changed since last time, return to get it reloaded. + // Note that depending on how you move the file into place, you might + // end up corrupting the one you're already playing, so this path + // might not trigger. + if (changed_since(pathname, last_modified)) { + return true; + } + internal_rewind(); + continue; + } + + VideoFormat video_format; + UniqueFrame video_frame; + if (!audio_only_stream) { + video_format = construct_video_format(frame.get(), video_timebase); + video_frame = make_video_frame(frame.get(), pathname, &error); + if (error) { + return false; + } + } + + int64_t frame_pts = audio_only_stream ? audio_pts : frame->pts; + AVRational timebase = audio_only_stream ? audio_timebase : video_timebase; + for ( ;; ) { // Try sending the frame in a loop as long as we get interrupted (then break). + if (last_pts == 0 && pts_origin == 0) { + pts_origin = frame_pts; + } + next_frame_start = compute_frame_start(frame_pts, pts_origin, timebase, start, rate); + if (audio_only_stream) { + audio_frame->received_timestamp = next_frame_start; + } else { + if (first_frame && last_frame_was_connected) { + // If reconnect took more than one second, this is probably a live feed, + // and we should reset the resampler. (Or the rate is really, really low, + // in which case a reset on the first frame is fine anyway.) + if (duration(next_frame_start - last_frame).count() >= 1.0) { + last_frame_was_connected = false; + } } - pts_origin = last_pts = 0; - start = next_frame_start = steady_clock::now(); - break; + video_frame->received_timestamp = next_frame_start; + + // The easiest way to get all the rate conversions etc. right is to move the + // audio PTS into the video PTS timebase and go from there. (We'll get some + // rounding issues, but they should not be a big problem.) + int64_t audio_pts_as_video_pts = av_rescale_q(audio_pts, audio_timebase, video_timebase); + audio_frame->received_timestamp = compute_frame_start(audio_pts_as_video_pts, pts_origin, video_timebase, start, rate); + + if (audio_frame->len != 0) { + // The received timestamps in Nageru are measured after we've just received the frame. + // However, pts (especially audio pts) is at the _beginning_ of the frame. + // If we have locked audio, the distinction doesn't really matter, as pts is + // on a relative scale and a fixed offset is fine. But if we don't, we will have + // a different number of samples each time, which will cause huge audio jitter + // and throw off the resampler. + // + // In a sense, we should have compensated by adding the frame and audio lengths + // to video_frame->received_timestamp and audio_frame->received_timestamp respectively, + // but that would mean extra waiting in sleep_until(). All we need is that they + // are correct relative to each other, though (and to the other frames we send), + // so just align the end of the audio frame, and we're fine. + size_t num_samples = (audio_frame->len * 8) / audio_format.bits_per_sample / audio_format.num_channels; + double offset = double(num_samples) / OUTPUT_FREQUENCY - + double(video_format.frame_rate_den) / video_format.frame_rate_nom; + audio_frame->received_timestamp += duration_cast(duration(offset)); + } + } - case QueuedCommand::CHANGE_RATE: - start = next_frame_start; - pts_origin = last_pts; - rate = cmd.new_rate; + steady_clock::time_point now = steady_clock::now(); + if (duration(now - next_frame_start).count() >= 0.1) { + // If we don't have enough CPU to keep up, or if we have a live stream + // where the initial origin was somehow wrong, we could be behind indefinitely. + // In particular, this will give the audio resampler problems as it tries + // to speed up to reduce the delay, hitting the low end of the buffer every time. + fprintf(stderr, "%s: Playback %.0f ms behind, resetting time scale\n", + pathname.c_str(), + 1e3 * duration(now - next_frame_start).count()); + pts_origin = frame_pts; + start = next_frame_start = now; + timecode += MAX_FPS * 2 + 1; + } + bool finished_wakeup = producer_thread_should_quit.sleep_until(next_frame_start); + if (finished_wakeup) { + if (audio_frame->len > 0) { + assert(audio_pts != -1); + } + if (!last_frame_was_connected) { + // We're recovering from an error (or really slow load, see above). + // Make sure to get the audio resampler reset. (This is a hack; + // ideally, the frame callback should just accept a way to signal + // audio discontinuity.) + timecode += MAX_FPS * 2 + 1; + } + frame_callback(frame_pts, video_timebase, audio_pts, audio_timebase, timecode++, + video_frame.get_and_release(), 0, video_format, + audio_frame.get_and_release(), 0, audio_format); + first_frame = false; + last_frame = steady_clock::now(); + last_frame_was_connected = true; break; + } else { + if (producer_thread_should_quit.should_quit()) break; + + bool rewound = false; + if (process_queued_commands(format_ctx.get(), pathname, last_modified, &rewound)) { + return true; + } + // If we just rewound, drop this frame on the floor and be done. + if (rewound) { + break; + } + // OK, we didn't, so probably a rate change. Recalculate next_frame_start, + // but if it's now in the past, we'll reset the origin, so that we don't + // generate a huge backlog of frames that we need to run through quickly. + next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate); + steady_clock::time_point now = steady_clock::now(); + if (next_frame_start < now) { + pts_origin = frame->pts; + start = next_frame_start = now; + } + } + } + last_pts = frame_pts; + } + return true; +} + +void FFmpegCapture::internal_rewind() +{ + pts_origin = last_pts = 0; + start = next_frame_start = steady_clock::now(); +} + +bool FFmpegCapture::process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified, bool *rewound) +{ + // Process any queued commands from other threads. + vector commands; + { + lock_guard lock(queue_mu); + swap(commands, command_queue); + } + for (const QueuedCommand &cmd : commands) { + switch (cmd.command) { + case QueuedCommand::REWIND: + if (av_seek_frame(format_ctx, /*stream_index=*/-1, /*timestamp=*/0, /*flags=*/0) < 0) { + fprintf(stderr, "%s: Rewind failed, stopping play.\n", pathname.c_str()); + } + // If the file has changed since last time, return to get it reloaded. + // Note that depending on how you move the file into place, you might + // end up corrupting the one you're already playing, so this path + // might not trigger. + if (changed_since(pathname, last_modified)) { + return true; } + internal_rewind(); + if (rewound != nullptr) { + *rewound = true; + } + break; + + case QueuedCommand::CHANGE_RATE: + // Change the origin to the last played frame. + start = compute_frame_start(last_pts, pts_origin, video_timebase, start, rate); + pts_origin = last_pts; + rate = cmd.new_rate; + break; } + } + return false; +} + +namespace { + +} // namespace - // Read packets until we have a frame or there are none left. - int frame_finished = 0; - AVFrameWithDeleter frame = av_frame_alloc_unique(); - bool eof = false; - do { - AVPacket pkt; - unique_ptr pkt_cleanup( - &pkt, av_packet_unref); - av_init_packet(&pkt); - pkt.data = nullptr; - pkt.size = 0; - if (av_read_frame(format_ctx.get(), &pkt) == 0) { - if (pkt.stream_index != video_stream_index) { - // Ignore audio for now. - continue; +AVFrameWithDeleter FFmpegCapture::decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, AVCodecContext *audio_codec_ctx, + const std::string &pathname, int video_stream_index, int audio_stream_index, + FrameAllocator::Frame *audio_frame, AudioFormat *audio_format, int64_t *audio_pts, bool *error) +{ + *error = false; + + // Read packets until we have a frame or there are none left. + bool frame_finished = false; + AVFrameWithDeleter audio_avframe = av_frame_alloc_unique(); + AVFrameWithDeleter video_avframe = av_frame_alloc_unique(); + bool eof = false; + *audio_pts = -1; + bool has_audio = false; + do { + AVPacket pkt; + unique_ptr pkt_cleanup( + &pkt, av_packet_unref); + av_init_packet(&pkt); + pkt.data = nullptr; + pkt.size = 0; + if (av_read_frame(format_ctx, &pkt) == 0) { + if (pkt.stream_index == audio_stream_index && audio_callback != nullptr) { + audio_callback(&pkt, format_ctx->streams[audio_stream_index]->time_base); + } + if (pkt.stream_index == video_stream_index) { + if (avcodec_send_packet(video_codec_ctx, &pkt) < 0) { + fprintf(stderr, "%s: Cannot send packet to video codec.\n", pathname.c_str()); + *error = true; + return AVFrameWithDeleter(nullptr); } - if (avcodec_send_packet(codec_ctx.get(), &pkt) < 0) { - fprintf(stderr, "%s: Cannot send packet to codec.\n", pathname.c_str()); - return false; + } else if (pkt.stream_index == audio_stream_index) { + has_audio = true; + if (avcodec_send_packet(audio_codec_ctx, &pkt) < 0) { + fprintf(stderr, "%s: Cannot send packet to audio codec.\n", pathname.c_str()); + *error = true; + return AVFrameWithDeleter(nullptr); + } + } + } else { + eof = true; // Or error, but ignore that for the time being. + } + + // Decode audio, if any. + if (has_audio) { + for ( ;; ) { + int err = avcodec_receive_frame(audio_codec_ctx, audio_avframe.get()); + if (err == 0) { + if (*audio_pts == -1) { + *audio_pts = audio_avframe->pts; + } + convert_audio(audio_avframe.get(), audio_frame, audio_format); + } else if (err == AVERROR(EAGAIN)) { + break; + } else { + fprintf(stderr, "%s: Cannot receive frame from audio codec.\n", pathname.c_str()); + *error = true; + return AVFrameWithDeleter(nullptr); } - } else { - eof = true; // Or error, but ignore that for the time being. } + } - int err = avcodec_receive_frame(codec_ctx.get(), frame.get()); + if (video_codec_ctx != nullptr) { + // Decode video, if we have a frame. + int err = avcodec_receive_frame(video_codec_ctx, video_avframe.get()); if (err == 0) { frame_finished = true; break; } else if (err != AVERROR(EAGAIN)) { - fprintf(stderr, "%s: Cannot receive frame from codec.\n", pathname.c_str()); - return false; + fprintf(stderr, "%s: Cannot receive frame from video codec.\n", pathname.c_str()); + *error = true; + return AVFrameWithDeleter(nullptr); } - } while (!eof); + } else { + return AVFrameWithDeleter(nullptr); + } + } while (!eof); - if (!frame_finished) { - // EOF. Loop back to the start if we can. - if (av_seek_frame(format_ctx.get(), /*stream_index=*/-1, /*timestamp=*/0, /*flags=*/0) < 0) { - fprintf(stderr, "%s: Rewind failed, not looping.\n", pathname.c_str()); - return true; - } - pts_origin = last_pts = 0; - start = steady_clock::now(); - continue; + if (frame_finished) + return video_avframe; + else + return AVFrameWithDeleter(nullptr); +} + +void FFmpegCapture::convert_audio(const AVFrame *audio_avframe, FrameAllocator::Frame *audio_frame, AudioFormat *audio_format) +{ + // Decide on a format. If there already is one in this audio frame, + // we're pretty much forced to use it. If not, we try to find an exact match. + // If that still doesn't work, we default to 32-bit signed chunked + // (float would be nice, but there's really no way to signal that yet). + AVSampleFormat dst_format; + if (audio_format->bits_per_sample == 0) { + switch (audio_avframe->format) { + case AV_SAMPLE_FMT_S16: + case AV_SAMPLE_FMT_S16P: + audio_format->bits_per_sample = 16; + dst_format = AV_SAMPLE_FMT_S16; + break; + case AV_SAMPLE_FMT_S32: + case AV_SAMPLE_FMT_S32P: + default: + audio_format->bits_per_sample = 32; + dst_format = AV_SAMPLE_FMT_S32; + break; } + } else if (audio_format->bits_per_sample == 16) { + dst_format = AV_SAMPLE_FMT_S16; + } else if (audio_format->bits_per_sample == 32) { + dst_format = AV_SAMPLE_FMT_S32; + } else { + assert(false); + } + audio_format->num_channels = 2; - if (sws_ctx == nullptr || sws_last_width != frame->width || sws_last_height != frame->height) { - sws_ctx.reset( - sws_getContext(frame->width, frame->height, (AVPixelFormat)frame->format, - width, height, AV_PIX_FMT_RGBA, - SWS_BICUBIC, nullptr, nullptr, nullptr)); - sws_last_width = frame->width; - sws_last_height = frame->height; + int64_t channel_layout = audio_avframe->channel_layout; + if (channel_layout == 0) { + channel_layout = av_get_default_channel_layout(audio_avframe->channels); + } + + if (resampler == nullptr || + audio_avframe->format != last_src_format || + dst_format != last_dst_format || + channel_layout != last_channel_layout || + av_frame_get_sample_rate(audio_avframe) != last_sample_rate) { + avresample_free(&resampler); + resampler = avresample_alloc_context(); + if (resampler == nullptr) { + fprintf(stderr, "Allocating resampler failed.\n"); + exit(1); } - if (sws_ctx == nullptr) { - fprintf(stderr, "%s: Could not create scaler context\n", pathname.c_str()); - return false; + + av_opt_set_int(resampler, "in_channel_layout", channel_layout, 0); + av_opt_set_int(resampler, "out_channel_layout", AV_CH_LAYOUT_STEREO_DOWNMIX, 0); + av_opt_set_int(resampler, "in_sample_rate", av_frame_get_sample_rate(audio_avframe), 0); + av_opt_set_int(resampler, "out_sample_rate", OUTPUT_FREQUENCY, 0); + av_opt_set_int(resampler, "in_sample_fmt", audio_avframe->format, 0); + av_opt_set_int(resampler, "out_sample_fmt", dst_format, 0); + + if (avresample_open(resampler) < 0) { + fprintf(stderr, "Could not open resample context.\n"); + exit(1); } - VideoFormat video_format; - video_format.width = width; - video_format.height = height; + last_src_format = AVSampleFormat(audio_avframe->format); + last_dst_format = dst_format; + last_channel_layout = channel_layout; + last_sample_rate = av_frame_get_sample_rate(audio_avframe); + } + + size_t bytes_per_sample = (audio_format->bits_per_sample / 8) * 2; + size_t num_samples_room = (audio_frame->size - audio_frame->len) / bytes_per_sample; + + uint8_t *data = audio_frame->data + audio_frame->len; + int out_samples = avresample_convert(resampler, &data, 0, num_samples_room, + const_cast(audio_avframe->data), audio_avframe->linesize[0], audio_avframe->nb_samples); + if (out_samples < 0) { + fprintf(stderr, "Audio conversion failed.\n"); + exit(1); + } + + audio_frame->len += out_samples * bytes_per_sample; +} + +VideoFormat FFmpegCapture::construct_video_format(const AVFrame *frame, AVRational video_timebase) +{ + VideoFormat video_format; + video_format.width = width; + video_format.height = height; + if (pixel_format == bmusb::PixelFormat_8BitBGRA) { video_format.stride = width * 4; - video_format.frame_rate_nom = video_timebase.den; - video_format.frame_rate_den = av_frame_get_pkt_duration(frame.get()) * video_timebase.num; - video_format.has_signal = true; - video_format.is_connected = true; - - next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate); - last_pts = frame->pts; - - FrameAllocator::Frame video_frame = video_frame_allocator->alloc_frame(); - if (video_frame.data != nullptr) { - uint8_t *pic_data[4] = { video_frame.data, nullptr, nullptr, nullptr }; - int linesizes[4] = { int(video_format.stride), 0, 0, 0 }; - sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes); - video_frame.len = video_format.stride * height; - video_frame.received_timestamp = next_frame_start; - } + } else if (pixel_format == FFmpegCapture::PixelFormat_NV12) { + video_format.stride = width; + } else { + assert(pixel_format == bmusb::PixelFormat_8BitYCbCrPlanar); + video_format.stride = width; + } + video_format.frame_rate_nom = video_timebase.den; + video_format.frame_rate_den = av_frame_get_pkt_duration(frame) * video_timebase.num; + if (video_format.frame_rate_nom == 0 || video_format.frame_rate_den == 0) { + // Invalid frame rate. + video_format.frame_rate_nom = 60; + video_format.frame_rate_den = 1; + } + video_format.has_signal = true; + video_format.is_connected = true; + return video_format; +} - FrameAllocator::Frame audio_frame; - AudioFormat audio_format; - audio_format.bits_per_sample = 32; - audio_format.num_channels = 8; +UniqueFrame FFmpegCapture::make_video_frame(const AVFrame *frame, const string &pathname, bool *error) +{ + *error = false; - producer_thread_should_quit.sleep_until(next_frame_start); - frame_callback(timecode++, - video_frame, 0, video_format, - audio_frame, 0, audio_format); + UniqueFrame video_frame(video_frame_allocator->alloc_frame()); + if (video_frame->data == nullptr) { + return video_frame; } - return true; + + if (sws_ctx == nullptr || + sws_last_width != frame->width || + sws_last_height != frame->height || + sws_last_src_format != frame->format) { + sws_dst_format = decide_dst_format(AVPixelFormat(frame->format), pixel_format); + sws_ctx.reset( + sws_getContext(frame->width, frame->height, AVPixelFormat(frame->format), + width, height, sws_dst_format, + SWS_BICUBIC, nullptr, nullptr, nullptr)); + sws_last_width = frame->width; + sws_last_height = frame->height; + sws_last_src_format = frame->format; + } + if (sws_ctx == nullptr) { + fprintf(stderr, "%s: Could not create scaler context\n", pathname.c_str()); + *error = true; + return video_frame; + } + + uint8_t *pic_data[4] = { nullptr, nullptr, nullptr, nullptr }; + int linesizes[4] = { 0, 0, 0, 0 }; + if (pixel_format == bmusb::PixelFormat_8BitBGRA) { + pic_data[0] = video_frame->data; + linesizes[0] = width * 4; + video_frame->len = (width * 4) * height; + } else if (pixel_format == PixelFormat_NV12) { + pic_data[0] = video_frame->data; + linesizes[0] = width; + + pic_data[1] = pic_data[0] + width * height; + linesizes[1] = width; + + video_frame->len = (width * 2) * height; + + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(sws_dst_format); + current_frame_ycbcr_format = decode_ycbcr_format(desc, frame); + } else { + assert(pixel_format == bmusb::PixelFormat_8BitYCbCrPlanar); + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(sws_dst_format); + + int chroma_width = AV_CEIL_RSHIFT(int(width), desc->log2_chroma_w); + int chroma_height = AV_CEIL_RSHIFT(int(height), desc->log2_chroma_h); + + pic_data[0] = video_frame->data; + linesizes[0] = width; + + pic_data[1] = pic_data[0] + width * height; + linesizes[1] = chroma_width; + + pic_data[2] = pic_data[1] + chroma_width * chroma_height; + linesizes[2] = chroma_width; + + video_frame->len = width * height + 2 * chroma_width * chroma_height; + + current_frame_ycbcr_format = decode_ycbcr_format(desc, frame); + } + sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes); + + return video_frame; +} + +int FFmpegCapture::interrupt_cb_thunk(void *unique) +{ + return reinterpret_cast(unique)->interrupt_cb(); +} + +int FFmpegCapture::interrupt_cb() +{ + return should_interrupt.load(); }