Detect the cropped picture size in the h.264 parser.

This removes one instance of hardcoded 1088->1080 translation. Refs #11358.
MythTV · Mar 4, 2013 · cc7d774 · cc7d774
1 parent b174418
commit cc7d774
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Showing 3 changed files with 31 additions and 5 deletions.
diff --git a/mythtv/libs/libmythtv/avformatdecoder.cpp b/mythtv/libs/libmythtv/avformatdecoder.cpp
@@ -3126,10 +3126,8 @@ int AvFormatDecoder::H264PreProcessPkt(AVStream *stream, AVPacket *pkt)
         }
 
         current_aspect = get_aspect(*m_h264_parser);
-        uint  width  = m_h264_parser->pictureWidth();
-        uint  height = m_h264_parser->pictureHeight();
-        if (height == 1088 && current_height == 1080)
-            height = 1080;
+        uint  width  = m_h264_parser->pictureWidthCropped();
+        uint  height = m_h264_parser->pictureHeightCropped();
         float seqFPS = m_h264_parser->frameRate();
 
         bool res_changed = ((width  != (uint)current_width) ||

diff --git a/mythtv/libs/libmythtv/mpeg/H264Parser.cpp b/mythtv/libs/libmythtv/mpeg/H264Parser.cpp
@@ -130,6 +130,7 @@ void H264Parser::Reset(void)
 
     delta_pic_order_always_zero_flag = 0;
     separate_colour_plane_flag = 0;
+    chroma_format_idc = 1;
     frame_mbs_only_flag = -1;
     pic_order_present_flag = -1;
     redundant_pic_cnt_present_flag = 0;
@@ -758,7 +759,7 @@ bool H264Parser::decode_Header(GetBitContext *gb)
  */
 void H264Parser::decode_SPS(GetBitContext * gb)
 {
-    int profile_idc, chroma_format_idc;
+    int profile_idc;
 
     seen_sps = true;
 
@@ -1340,3 +1341,27 @@ uint H264Parser::aspectRatio(void) const
 
     return aspect * 1000000;
 }
+
+// Following the lead of libavcodec, ignore the left cropping.
+uint H264Parser::pictureWidthCropped(void) const
+{
+    uint ChromaArrayType = separate_colour_plane_flag ? 0 : chroma_format_idc;
+    uint CropUnitX = 1;
+    uint SubWidthC = chroma_format_idc == 3 ? 1 : 2;
+    if (ChromaArrayType != 0)
+        CropUnitX = SubWidthC;
+    uint crop = CropUnitX * frame_crop_right_offset;
+    return pic_width - crop;
+}
+
+// Following the lead of libavcodec, ignore the top cropping.
+uint H264Parser::pictureHeightCropped(void) const
+{
+    uint ChromaArrayType = separate_colour_plane_flag ? 0 : chroma_format_idc;
+    uint CropUnitY = 2 - frame_mbs_only_flag;
+    uint SubHeightC = chroma_format_idc <= 1 ? 2 : 1;
+    if (ChromaArrayType != 0)
+        CropUnitY *= SubHeightC;
+    uint crop = CropUnitY * frame_crop_bottom_offset;
+    return pic_height - crop;
+}
diff --git a/mythtv/libs/libmythtv/mpeg/H264Parser.h b/mythtv/libs/libmythtv/mpeg/H264Parser.h
@@ -136,6 +136,8 @@ class H264Parser {
 
     uint pictureWidth(void) const { return pic_width; }
     uint pictureHeight(void) const { return pic_height; }
+    uint pictureWidthCropped(void) const;
+    uint pictureHeightCropped(void) const;
 
     /** \brief Computes aspect ratio from picture size and sample aspect ratio
      */
@@ -229,6 +231,7 @@ class H264Parser {
     int8_t     frame_mbs_only_flag;
     int8_t     pic_order_present_flag;
     int8_t     redundant_pic_cnt_present_flag;
+    int8_t     chroma_format_idc;
 
     uint       num_ref_frames;
     uint       redundant_pic_cnt;