Suppress repeated chroma location warnings from FFmpeg.

It's no good getting one of these for every frame. This works around
an FFmpeg bug where HEVC doesn't get the right chroma location set.

diff --git a/nageru/ffmpeg_capture.cpp b/nageru/ffmpeg_capture.cpp
index 87d1c007e9142a07e21b2c49820c706709b45c26..c6824069aedc8786954531e3fb1f8f62deb52391 100644 (file)
--- a/nageru/ffmpeg_capture.cpp
+++ b/nageru/ffmpeg_capture.cpp
@@ -143,7 +143,7 @@ AVPixelFormat decide_dst_format(AVPixelFormat src_format, bmusb::PixelFormat dst
        return av_get_pix_fmt(best_format);
 }
 
-YCbCrFormat decode_ycbcr_format(const AVPixFmtDescriptor *desc, const AVFrame *frame, bool is_mjpeg)
+YCbCrFormat decode_ycbcr_format(const AVPixFmtDescriptor *desc, const AVFrame *frame, bool is_mjpeg, AVColorSpace *last_colorspace, AVChromaLocation *last_chroma_location)
 {
        YCbCrFormat format;
        AVColorSpace colorspace = frame->colorspace;
@@ -163,11 +163,14 @@ YCbCrFormat decode_ycbcr_format(const AVPixFmtDescriptor *desc, const AVFrame *f
                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);
+               if (colorspace != *last_colorspace) {
+                       fprintf(stderr, "Unknown Y'CbCr coefficient enum %d from FFmpeg; choosing Rec. 709.\n",
+                               colorspace);
+               }
                format.luma_coefficients = YCBCR_REC_709;
                break;
        }
+       *last_colorspace = colorspace;
 
        format.full_range = is_full_range(desc);
        format.num_levels = 1 << desc->comp[0].depth;
@@ -200,12 +203,15 @@ YCbCrFormat decode_ycbcr_format(const AVPixFmtDescriptor *desc, const AVFrame *f
                format.cb_y_position = 1.0;
                break;
        default:
-               fprintf(stderr, "Unknown chroma location coefficient enum %d from FFmpeg; choosing center.\n",
-                       frame->chroma_location);
+               if (frame->chroma_location != *last_chroma_location) {
+                       fprintf(stderr, "Unknown chroma location coefficient enum %d from FFmpeg; choosing center.\n",
+                               frame->chroma_location);
+               }
                format.cb_x_position = 0.5;
                format.cb_y_position = 0.5;
                break;
        }
+       *last_chroma_location = frame->chroma_location;
 
        if (is_mjpeg && !format.full_range) {
                // Limited-range MJPEG is only detected by FFmpeg whenever a special
@@ -459,6 +465,8 @@ bool FFmpegCapture::play_video(const string &pathname)
        } else {
                last_modified = buf.st_mtim;
        }
+       last_colorspace = static_cast<AVColorSpace>(-1);
+       last_chroma_location = static_cast<AVChromaLocation>(-1);
 
        AVFormatContextWithCloser format_ctx;
        if (srt_sock == -1) {
@@ -1002,7 +1010,7 @@ UniqueFrame FFmpegCapture::make_video_frame(const AVFrame *frame, const string &
                video_frame->len = (frame_width(frame) * 2) * frame_height(frame);
 
                const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(sws_dst_format);
-               current_frame_ycbcr_format = decode_ycbcr_format(desc, frame, is_mjpeg);
+               current_frame_ycbcr_format = decode_ycbcr_format(desc, frame, is_mjpeg, &last_colorspace, &last_chroma_location);
        } else {
                assert(pixel_format == bmusb::PixelFormat_8BitYCbCrPlanar);
                const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(sws_dst_format);
@@ -1021,7 +1029,7 @@ UniqueFrame FFmpegCapture::make_video_frame(const AVFrame *frame, const string &
 
                video_frame->len = frame_width(frame) * frame_height(frame) + 2 * chroma_width * chroma_height;
 
-               current_frame_ycbcr_format = decode_ycbcr_format(desc, frame, is_mjpeg);
+               current_frame_ycbcr_format = decode_ycbcr_format(desc, frame, is_mjpeg, &last_colorspace, &last_chroma_location);
        }
        sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes);
 

diff --git a/nageru/ffmpeg_capture.h b/nageru/ffmpeg_capture.h
index 4cddbfddf757bce77a1f49b6c21b52bd7b57675b..1fc8f7128f516d6b4d06431b3049256f7bbdf7f7 100644 (file)
--- a/nageru/ffmpeg_capture.h
+++ b/nageru/ffmpeg_capture.h
@@ -329,6 +329,11 @@ private:
        std::string last_subtitle;
 
        movit::RGBTriplet last_neutral_color{1.0f, 1.0f, 1.0f};
+
+       // Used for suppressing repeated warnings. Reset when a video starts playing.
+       // -1 is strictly speaking outside the range of the enum, but hopefully, it will be alright.
+       AVColorSpace last_colorspace = static_cast<AVColorSpace>(-1);
+       AVChromaLocation last_chroma_location = static_cast<AVChromaLocation>(-1);
 };
 
 #endif  // !defined(_FFMPEG_CAPTURE_H)