videoio/FFmpeg: added CV_16UC1 read/write support

modules/videoio/src/cap_ffmpeg.cpp

@@ -54,6 +54,7 @@
 #define icvReleaseCapture_FFMPEG_p cvReleaseCapture_FFMPEG
 #define icvGrabFrame_FFMPEG_p cvGrabFrame_FFMPEG
 #define icvRetrieveFrame_FFMPEG_p cvRetrieveFrame_FFMPEG
+#define icvRetrieveFrame2_FFMPEG_p cvRetrieveFrame2_FFMPEG
 #define icvSetCaptureProperty_FFMPEG_p cvSetCaptureProperty_FFMPEG
 #define icvGetCaptureProperty_FFMPEG_p cvGetCaptureProperty_FFMPEG
 #define icvCreateVideoWriter_FFMPEG_p cvCreateVideoWriter_FFMPEG
@@ -90,7 +91,7 @@ public:
     virtual bool retrieveFrame(int flag, cv::OutputArray frame) CV_OVERRIDE
     {
         unsigned char* data = 0;
-        int step=0, width=0, height=0, cn=0;
+        int step=0, width=0, height=0, cn=0, depth=0;
 
         if (!ffmpegCapture)
             return false;
@@ -103,15 +104,15 @@ public:
         }
 
         if (flag == 0) {
-            if (!icvRetrieveFrame_FFMPEG_p(ffmpegCapture, &data, &step, &width, &height, &cn))
+            if (!icvRetrieveFrame2_FFMPEG_p(ffmpegCapture, &data, &step, &width, &height, &cn, &depth))
                 return false;
         }
         else {
-            if (!ffmpegCapture->retrieveFrame(flag, &data, &step, &width, &height, &cn))
+            if (!ffmpegCapture->retrieveFrame(flag, &data, &step, &width, &height, &cn, &depth))
                 return false;
         }
 
-        cv::Mat tmp(height, width, CV_MAKETYPE(CV_8U, cn), data, step);
+        cv::Mat tmp(height, width, CV_MAKETYPE(depth, cn), data, step);
         applyMetadataRotation(*this, tmp);
         tmp.copyTo(frame);
 
@@ -165,7 +166,7 @@ public:
     {
         if(!ffmpegWriter)
             return;
-        CV_Assert(image.depth() == CV_8U);
+        CV_Assert(image.depth() == CV_8U || image.depth() == CV_16U);
 
         // if UMat, try GPU to GPU copy using OpenCL extensions
         if (image.isUMat()) {

modules/videoio/src/cap_ffmpeg_impl.hpp

@@ -414,7 +414,6 @@ struct Image_FFMPEG
     int step;
     int width;
     int height;
-    int cn;
 };
 
 
@@ -556,7 +555,7 @@ struct CvCapture_FFMPEG
     double getProperty(int) const;
     bool setProperty(int, double);
     bool grabFrame();
-    bool retrieveFrame(int flag, unsigned char** data, int* step, int* width, int* height, int* cn);
+    bool retrieveFrame(int flag, unsigned char** data, int* step, int* width, int* height, int* cn, int* depth);
     bool retrieveHWFrame(cv::OutputArray output);
     void rotateFrame(cv::Mat &mat) const;
 
@@ -614,6 +613,7 @@ struct CvCapture_FFMPEG
     bool processRawPacket();
     bool rawMode;
     bool rawModeInitialized;
+    bool convertRGB;
     AVPacket packet_filtered;
 #if LIBAVFORMAT_BUILD >= CALC_FFMPEG_VERSION(58, 20, 100)
     AVBSFContext* bsfc;
@@ -666,6 +666,7 @@ void CvCapture_FFMPEG::init()
 
     rawMode = false;
     rawModeInitialized = false;
+    convertRGB = true;
     memset(&packet_filtered, 0, sizeof(packet_filtered));
     av_init_packet(&packet_filtered);
     bsfc = NULL;
@@ -1042,6 +1043,15 @@ bool CvCapture_FFMPEG::open(const char* _filename, const VideoCaptureParameters&
 
     if (!params.empty())
     {
+        convertRGB = params.get<bool>(CAP_PROP_CONVERT_RGB, true);
+        if (!convertRGB)
+        {
+            CV_LOG_WARNING(NULL, "VIDEOIO/FFMPEG: BGR conversion turned OFF, decoded frame will be "
+                                 "returned in its original format. "
+                                 "Multiplanar formats are not supported by the backend. "
+                                 "Only GRAY8/GRAY16LE pixel formats have been tested. "
+                                 "Use at your own risk.");
+        }
         if (params.has(CAP_PROP_FORMAT))
         {
             int value = params.get<int>(CAP_PROP_FORMAT);
@@ -1309,7 +1319,6 @@ bool CvCapture_FFMPEG::open(const char* _filename, const VideoCaptureParameters&
 
             frame.width = context->width;
             frame.height = context->height;
-            frame.cn = 3;
             frame.step = 0;
             frame.data = NULL;
             get_rotation_angle();
@@ -1560,7 +1569,7 @@ bool CvCapture_FFMPEG::grabFrame()
     return valid;
 }
 
-bool CvCapture_FFMPEG::retrieveFrame(int flag, unsigned char** data, int* step, int* width, int* height, int* cn)
+bool CvCapture_FFMPEG::retrieveFrame(int flag, unsigned char** data, int* step, int* width, int* height, int* cn, int* depth)
 {
     if (!video_st || !context)
         return false;
@@ -1581,6 +1590,7 @@ bool CvCapture_FFMPEG::retrieveFrame(int flag, unsigned char** data, int* step,
         *width = *step;
         *height = 1;
         *cn = 1;
+        *depth = CV_8U;
         return  ret;
     }
 
@@ -1600,6 +1610,21 @@ bool CvCapture_FFMPEG::retrieveFrame(int flag, unsigned char** data, int* step,
     if (!sw_picture || !sw_picture->data[0])
         return false;
 
+    CV_LOG_DEBUG(NULL, "Input picture format: " << av_get_pix_fmt_name((AVPixelFormat)sw_picture->format));
+    const AVPixelFormat result_format = convertRGB ? AV_PIX_FMT_BGR24 : (AVPixelFormat)sw_picture->format;
+    switch (result_format)
+    {
+    case AV_PIX_FMT_BGR24: *depth = CV_8U; *cn = 3; break;
+    case AV_PIX_FMT_GRAY8: *depth = CV_8U; *cn = 1; break;
+    case AV_PIX_FMT_GRAY16LE: *depth = CV_16U; *cn = 1; break;
+    default:
+        CV_LOG_WARNING(NULL, "Unknown/unsupported picture format: " << av_get_pix_fmt_name(result_format)
+                       << ", will be treated as 8UC1.");
+        *depth = CV_8U;
+        *cn = 1;
+        break; // TODO: return false?
+    }
+
     if( img_convert_ctx == NULL ||
         frame.width != video_st->CV_FFMPEG_CODEC_FIELD->width ||
         frame.height != video_st->CV_FFMPEG_CODEC_FIELD->height ||
@@ -1614,7 +1639,7 @@ bool CvCapture_FFMPEG::retrieveFrame(int flag, unsigned char** data, int* step,
                 buffer_width, buffer_height,
                 (AVPixelFormat)sw_picture->format,
                 buffer_width, buffer_height,
-                AV_PIX_FMT_BGR24,
+                result_format,
                 SWS_BICUBIC,
                 NULL, NULL, NULL
                 );
@@ -1624,7 +1649,7 @@ bool CvCapture_FFMPEG::retrieveFrame(int flag, unsigned char** data, int* step,
 
 #if USE_AV_FRAME_GET_BUFFER
         av_frame_unref(&rgb_picture);
-        rgb_picture.format = AV_PIX_FMT_BGR24;
+        rgb_picture.format = result_format;
         rgb_picture.width = buffer_width;
         rgb_picture.height = buffer_height;
         if (0 != av_frame_get_buffer(&rgb_picture, 32))
@@ -1636,14 +1661,13 @@ bool CvCapture_FFMPEG::retrieveFrame(int flag, unsigned char** data, int* step,
         int aligns[AV_NUM_DATA_POINTERS];
         avcodec_align_dimensions2(video_st->codec, &buffer_width, &buffer_height, aligns);
         rgb_picture.data[0] = (uint8_t*)realloc(rgb_picture.data[0],
-                _opencv_ffmpeg_av_image_get_buffer_size( AV_PIX_FMT_BGR24,
+                _opencv_ffmpeg_av_image_get_buffer_size( result_format,
                                     buffer_width, buffer_height ));
         _opencv_ffmpeg_av_image_fill_arrays(&rgb_picture, rgb_picture.data[0],
-                        AV_PIX_FMT_BGR24, buffer_width, buffer_height );
+                        result_format, buffer_width, buffer_height );
 #endif
         frame.width = video_st->CV_FFMPEG_CODEC_FIELD->width;
         frame.height = video_st->CV_FFMPEG_CODEC_FIELD->height;
-        frame.cn = 3;
         frame.data = rgb_picture.data[0];
         frame.step = rgb_picture.linesize[0];
     }
@@ -1661,7 +1685,6 @@ bool CvCapture_FFMPEG::retrieveFrame(int flag, unsigned char** data, int* step,
     *step = frame.step;
     *width = frame.width;
     *height = frame.height;
-    *cn = frame.cn;
 
 #if USE_AV_HW_CODECS
     if (sw_picture != picture)
@@ -1766,6 +1789,8 @@ double CvCapture_FFMPEG::getProperty( int property_id ) const
         if (rawMode)
             return -1;
         break;
+    case CAP_PROP_CONVERT_RGB:
+        return convertRGB;
     case CAP_PROP_LRF_HAS_KEY_FRAME: {
         const AVPacket& p = bsfc ? packet_filtered : packet;
         return ((p.flags & AV_PKT_FLAG_KEY) != 0) ? 1 : 0;
@@ -1984,6 +2009,9 @@ bool CvCapture_FFMPEG::setProperty( int property_id, double value )
         if (value == -1)
             return setRaw();
         return false;
+    case CAP_PROP_CONVERT_RGB:
+        convertRGB = (value != 0);
+        return true;
     case CAP_PROP_ORIENTATION_AUTO:
 #if LIBAVUTIL_BUILD >= CALC_FFMPEG_VERSION(52, 94, 100)
         rotation_auto = value != 0 ? true : false;
@@ -2218,7 +2246,6 @@ static AVCodecContext * icv_configure_video_stream_FFMPEG(AVFormatContext *oc,
 
     c->gop_size = 12; /* emit one intra frame every twelve frames at most */
     c->pix_fmt = pixel_format;
-
     if (c->codec_id == CV_CODEC(CODEC_ID_MPEG2VIDEO)) {
         c->max_b_frames = 2;
     }
@@ -2351,12 +2378,15 @@ bool CvVideoWriter_FFMPEG::writeFrame( const unsigned char* data, int step, int
             return false;
         }
     }
-    else if (input_pix_fmt == AV_PIX_FMT_GRAY8) {
+    else if (input_pix_fmt == AV_PIX_FMT_GRAY8 || input_pix_fmt == AV_PIX_FMT_GRAY16LE) {
         if (cn != 1) {
             return false;
         }
     }
     else {
+        CV_LOG_WARNING(NULL, "Input data does not match selected pixel format: "
+                       << av_get_pix_fmt_name(input_pix_fmt)
+                       << ", number of channels: " << cn);
         CV_Assert(false);
     }
 
@@ -2656,6 +2686,14 @@ bool CvVideoWriter_FFMPEG::open( const char * filename, int fourcc,
     close();
 
     const bool is_color = params.get(VIDEOWRITER_PROP_IS_COLOR, true);
+    const int depth = params.get(VIDEOWRITER_PROP_DEPTH, CV_8U);
+    const bool is_supported = depth == CV_8U || (depth == CV_16U && !is_color);
+    if (!is_supported)
+    {
+        CV_LOG_WARNING(NULL, "Unsupported depth/isColor combination is selected, "
+                             "only CV_8UC1/CV_8UC3/CV_16UC1 are supported.");
+        return false;
+    }
     if (params.has(VIDEOWRITER_PROP_HW_ACCELERATION))
     {
         va_type = params.get<VideoAccelerationType>(VIDEOWRITER_PROP_HW_ACCELERATION, VIDEO_ACCELERATION_NONE);
@@ -2713,12 +2751,28 @@ bool CvVideoWriter_FFMPEG::open( const char * filename, int fourcc,
         return false;
 
     /* determine optimal pixel format */
-    if (is_color) {
-        input_pix_fmt = AV_PIX_FMT_BGR24;
+    if (is_color)
+    {
+        switch (depth)
+        {
+        case CV_8U: input_pix_fmt = AV_PIX_FMT_BGR24; break;
+        default:
+            CV_LOG_WARNING(NULL, "Unsupported input depth for color image: " << depth);
+            return false;
         }
-    else {
-        input_pix_fmt = AV_PIX_FMT_GRAY8;
     }
+    else
+    {
+        switch (depth)
+        {
+        case CV_8U: input_pix_fmt = AV_PIX_FMT_GRAY8; break;
+        case CV_16U: input_pix_fmt = AV_PIX_FMT_GRAY16LE; break;
+        default:
+            CV_LOG_WARNING(NULL, "Unsupported input depth for grayscale image: " << depth);
+            return false;
+        }
+    }
+    CV_LOG_DEBUG(NULL, "Selected pixel format: " << av_get_pix_fmt_name(input_pix_fmt));
 
     if (fourcc == -1)
     {
@@ -3158,7 +3212,13 @@ int cvGrabFrame_FFMPEG(CvCapture_FFMPEG* capture)
 
 int cvRetrieveFrame_FFMPEG(CvCapture_FFMPEG* capture, unsigned char** data, int* step, int* width, int* height, int* cn)
 {
-    return capture->retrieveFrame(0, data, step, width, height, cn);
+    int depth = CV_8U;
+    return cvRetrieveFrame2_FFMPEG(capture, data, step, width, height, cn, &depth);
+}
+
+int cvRetrieveFrame2_FFMPEG(CvCapture_FFMPEG* capture, unsigned char** data, int* step, int* width, int* height, int* cn, int* depth)
+{
+    return capture->retrieveFrame(0, data, step, width, height, cn, depth);
 }
 
 static CvVideoWriter_FFMPEG* cvCreateVideoWriterWithParams_FFMPEG( const char* filename, int fourcc, double fps,

modules/videoio/src/cap_ffmpeg_legacy_api.hpp

@@ -31,6 +31,8 @@ OPENCV_FFMPEG_API double cvGetCaptureProperty_FFMPEG(struct CvCapture_FFMPEG* ca
 OPENCV_FFMPEG_API int cvGrabFrame_FFMPEG(struct CvCapture_FFMPEG* cap);
 OPENCV_FFMPEG_API int cvRetrieveFrame_FFMPEG(struct CvCapture_FFMPEG* capture, unsigned char** data,
                                              int* step, int* width, int* height, int* cn);
+OPENCV_FFMPEG_API int cvRetrieveFrame2_FFMPEG(struct CvCapture_FFMPEG* capture, unsigned char** data,
+                                              int* step, int* width, int* height, int* cn, int* depth);
 OPENCV_FFMPEG_API void cvReleaseCapture_FFMPEG(struct CvCapture_FFMPEG** cap);
 
 OPENCV_FFMPEG_API struct CvVideoWriter_FFMPEG* cvCreateVideoWriter_FFMPEG(const char* filename,

modules/videoio/test/test_ffmpeg.cpp

@@ -69,7 +69,9 @@ const FourCC_Ext_Size entries[] =
     make_tuple("mp4v", "avi", bigSize),
     make_tuple("MPEG", "avi", Size(720, 576)),
     make_tuple("XVID", "avi", bigSize),
-    make_tuple("H264", "mp4", Size(4096, 2160))
+    make_tuple("H264", "mp4", Size(4096, 2160)),
+    make_tuple("FFV1", "avi", bigSize),
+    make_tuple("FFV1", "mkv", bigSize)
 };
 
 INSTANTIATE_TEST_CASE_P(videoio, videoio_ffmpeg, testing::ValuesIn(entries));
@@ -560,4 +562,89 @@ TEST(videoio_ffmpeg, DISABLED_open_from_web)
     EXPECT_EQ((int)14315, n_frames);
 }
 
+
+typedef tuple<string, string, bool, bool> FourCC_Ext_Color_Support;
+typedef testing::TestWithParam< FourCC_Ext_Color_Support > videoio_ffmpeg_16bit;
+
+TEST_P(videoio_ffmpeg_16bit, basic)
+{
+    if (!videoio_registry::hasBackend(CAP_FFMPEG))
+        throw SkipTestException("FFmpeg backend was not found");
+
+    const int fourcc = fourccFromString(get<0>(GetParam()));
+    const string ext = string(".") + get<1>(GetParam());
+    const bool isColor = get<2>(GetParam());
+    const bool isSupported = get<3>(GetParam());
+    const int cn = isColor ? 3 : 1;
+    const int dataType = CV_16UC(cn);
+
+    const string filename = tempfile(ext.c_str());
+    const Size sz(640, 480);
+    const double fps = 30.0;
+    const double time_sec = 1;
+    const int numFrames = static_cast<int>(fps * time_sec);
+
+    {
+        VideoWriter writer;
+        writer.open(filename, CAP_FFMPEG, fourcc, fps, sz,
+                             {
+                                 VIDEOWRITER_PROP_DEPTH, CV_16U,
+                                 VIDEOWRITER_PROP_IS_COLOR, isColor
+                             });
+
+        ASSERT_EQ(isSupported, writer.isOpened());
+        if (isSupported)
+        {
+            Mat img(sz, dataType, Scalar::all(0));
+            const int coeff = cvRound(min(sz.width, sz.height)/(fps * time_sec));
+            for (int i = 0 ; i < numFrames; i++ )
+            {
+                rectangle(img,
+                          Point2i(coeff * i, coeff * i),
+                          Point2i(coeff * (i + 1), coeff * (i + 1)),
+                          Scalar::all(255 * (1.0 - static_cast<double>(i) / (fps * time_sec * 2))),
+                          -1);
+                writer << img;
+            }
+            writer.release();
+            EXPECT_GT(getFileSize(filename), 8192);
+        }
+    }
+
+    if (isSupported)
+    {
+        VideoCapture cap;
+        ASSERT_TRUE(cap.open(filename, CAP_FFMPEG, {CAP_PROP_CONVERT_RGB, false}));
+        ASSERT_TRUE(cap.isOpened());
+        Mat img;
+        bool res = true;
+        int numRead = 0;
+        while(res)
+        {
+            res = cap.read(img);
+            if (res)
+            {
+                ++numRead;
+                ASSERT_EQ(img.type(), dataType);
+                ASSERT_EQ(img.size(), sz);
+            }
+        }
+        ASSERT_EQ(numRead, numFrames);
+        remove(filename.c_str());
+    }
+}
+
+const FourCC_Ext_Color_Support sixteen_bit_modes[] =
+{
+    // 16-bit grayscale is supported
+    make_tuple("FFV1", "avi", false, true),
+    make_tuple("FFV1", "mkv", false, true),
+    // 16-bit color formats are NOT supported
+    make_tuple("FFV1", "avi", true, false),
+    make_tuple("FFV1", "mkv", true, false),
+
+};
+
+INSTANTIATE_TEST_CASE_P(/**/, videoio_ffmpeg_16bit, testing::ValuesIn(sixteen_bit_modes));
+
 }} // namespace

modules/videoio/test/test_video_io.cpp

@@ -411,6 +411,8 @@ static Ext_Fourcc_PSNR synthetic_params[] = {
     {"mkv", "XVID", 30.f, CAP_FFMPEG},
     {"mkv", "MPEG", 30.f, CAP_FFMPEG},
     {"mkv", "MJPG", 30.f, CAP_FFMPEG},
+    {"avi", "FFV1", 30.f, CAP_FFMPEG},
+    {"mkv", "FFV1", 30.f, CAP_FFMPEG},
 
     {"avi", "MPEG", 28.f, CAP_GSTREAMER},
     {"avi", "MJPG", 30.f, CAP_GSTREAMER},