]> git.sesse.net Git - nageru/blobdiff - ffmpeg_capture.cpp
Update the queue length metric after trimming, not before.
[nageru] / ffmpeg_capture.cpp
index 407f359104cff8444ac56cc9480c77c86366667c..fb1b223c326f4e789193da4e078c65a48d729ec5 100644 (file)
@@ -37,6 +37,7 @@ extern "C" {
 using namespace std;
 using namespace std::chrono;
 using namespace bmusb;
+using namespace movit;
 
 namespace {
 
@@ -59,10 +60,147 @@ bool changed_since(const std::string &pathname, const timespec &ts)
        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;
+       }
+
+       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<unsigned>::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;
@@ -213,7 +351,7 @@ bool FFmpegCapture::play_video(const string &pathname)
        }
 
        const AVCodecParameters *codecpar = format_ctx->streams[video_stream_index]->codecpar;
-       AVRational video_timebase = format_ctx->streams[video_stream_index]->time_base;
+       video_timebase = format_ctx->streams[video_stream_index]->time_base;
        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());
@@ -232,78 +370,19 @@ bool FFmpegCapture::play_video(const string &pathname)
                codec_ctx.get(), avcodec_close);
 
        internal_rewind();
-       double rate = 1.0;
-
-       unique_ptr<SwsContext, decltype(sws_freeContext)*> sws_ctx(nullptr, sws_freeContext);
-       int sws_last_width = -1, sws_last_height = -1;
 
        // Main loop.
        while (!producer_thread_should_quit.should_quit()) {
-               // Process any queued commands from other threads.
-               vector<QueuedCommand> commands;
-               {
-                       lock_guard<mutex> lock(queue_mu);
-                       swap(commands, command_queue);
+               if (process_queued_commands(format_ctx.get(), pathname, last_modified, /*rewound=*/nullptr)) {
+                       return true;
                }
-               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 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();
-                               break;
 
-                       case QueuedCommand::CHANGE_RATE:
-                               start = next_frame_start;
-                               pts_origin = last_pts;
-                               rate = cmd.new_rate;
-                               break;
-                       }
+               bool error;
+               AVFrameWithDeleter frame = decode_frame(format_ctx.get(), codec_ctx.get(), pathname, video_stream_index, &error);
+               if (error) {
+                       return false;
                }
-
-               // 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<AVPacket, decltype(av_packet_unref)*> 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;
-                               }
-                               if (avcodec_send_packet(codec_ctx.get(), &pkt) < 0) {
-                                       fprintf(stderr, "%s: Cannot send packet to codec.\n", pathname.c_str());
-                                       return false;
-                               }
-                       } else {
-                               eof = true;  // Or error, but ignore that for the time being.
-                       }
-
-                       int err = avcodec_receive_frame(codec_ctx.get(), frame.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;
-                       }
-               } while (!eof);
-
-               if (!frame_finished) {
+               if (frame == nullptr) {
                        // 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());
@@ -320,54 +399,50 @@ bool FFmpegCapture::play_video(const string &pathname)
                        continue;
                }
 
-               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_BGRA,
-                                       SWS_BICUBIC, nullptr, nullptr, nullptr));
-                       sws_last_width = frame->width;
-                       sws_last_height = frame->height;
-               }
-               if (sws_ctx == nullptr) {
-                       fprintf(stderr, "%s: Could not create scaler context\n", pathname.c_str());
+               VideoFormat video_format = construct_video_format(frame.get(), video_timebase);
+               FrameAllocator::Frame video_frame = make_video_frame(frame.get(), pathname, &error);
+               if (error) {
                        return false;
                }
 
-               VideoFormat video_format;
-               video_format.width = width;
-               video_format.height = height;
-               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;
-               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;
-
-               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;
-               }
-
                FrameAllocator::Frame audio_frame;
                AudioFormat audio_format;
                 audio_format.bits_per_sample = 32;
                 audio_format.num_channels = 8;
 
-               producer_thread_should_quit.sleep_until(next_frame_start);
-               frame_callback(timecode++,
-                       video_frame, 0, video_format,
-                       audio_frame, 0, audio_format);
+               for ( ;; ) {
+                       next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
+                       video_frame.received_timestamp = next_frame_start;
+                       bool finished_wakeup = producer_thread_should_quit.sleep_until(next_frame_start);
+                       if (finished_wakeup) {
+                               frame_callback(timecode++,
+                                       video_frame, 0, video_format,
+                                       audio_frame, 0, audio_format);
+                               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) {
+                                       video_frame_allocator->release_frame(video_frame);
+                                       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;
 }
@@ -377,3 +452,169 @@ 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<QueuedCommand> commands;
+       {
+               lock_guard<mutex> 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;
+}
+
+AVFrameWithDeleter FFmpegCapture::decode_frame(AVFormatContext *format_ctx, AVCodecContext *codec_ctx, const std::string &pathname, int video_stream_index, bool *error)
+{
+       *error = false;
+
+       // Read packets until we have a frame or there are none left.
+       bool frame_finished = false;
+       AVFrameWithDeleter frame = av_frame_alloc_unique();
+       bool eof = false;
+       do {
+               AVPacket pkt;
+               unique_ptr<AVPacket, decltype(av_packet_unref)*> 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 != video_stream_index) {
+                               // Ignore audio for now.
+                               continue;
+                       }
+                       if (avcodec_send_packet(codec_ctx, &pkt) < 0) {
+                               fprintf(stderr, "%s: Cannot send packet to 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, frame.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());
+                       *error = true;
+                       return AVFrameWithDeleter(nullptr);
+               }
+       } while (!eof);
+
+       if (frame_finished)
+               return frame;
+       else
+               return AVFrameWithDeleter(nullptr);
+}
+
+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;
+       } 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 FFmpegCapture::make_video_frame(const AVFrame *frame, const string &pathname, bool *error)
+{
+       *error = false;
+
+       FrameAllocator::Frame video_frame = video_frame_allocator->alloc_frame();
+       if (video_frame.data == nullptr) {
+               return video_frame;
+       }
+
+       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 {
+               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;
+}