[FFmpeg-devel] [PATCH] lavc/cfhd: added interlaced frame decoding

[Gagandeep Singh]

ticket #5522: interlaced frame required horizontal-temporal inverse
transform. though the output is not satisfactory yet.
---
 libavcodec/cfhd.c | 102 ++++++++++++++++++++++++++++++++++++++++++++----------
 libavcodec/cfhd.h |   3 +-
 2 files changed, 85 insertions(+), 20 deletions(-)

diff --git a/libavcodec/cfhd.c b/libavcodec/cfhd.c
index a064cd1599..b17c7c1dc5 100644
--- a/libavcodec/cfhd.c
+++ b/libavcodec/cfhd.c
@@ -50,8 +50,11 @@ enum CFHDParam {
     ChannelWidth     = 104,
     ChannelHeight    = 105,
     PrescaleShift    = 109,
+    Progressive      =  68,
 };
 
+
+
 static av_cold int cfhd_init(AVCodecContext *avctx)
 {
     CFHDContext *s = avctx->priv_data;
@@ -83,6 +86,7 @@ static void init_frame_defaults(CFHDContext *s)
     s->wavelet_depth     = 3;
     s->pshift            = 1;
     s->codebook          = 0;
+    s->progressive       = 0;
     init_plane_defaults(s);
 }
 
@@ -137,6 +141,28 @@ static inline void filter(int16_t *output, ptrdiff_t out_stride,
     }
 }
 
+static inline void interlaced_vertical_filter(int16_t *output, int16_t *low, int16_t *high,
+                         int width, int linesize, int plane)
+{
+    int i;
+    int16_t even, odd;
+    for (i = 0; i < width; i++) {
+
+
+      even = (*low - *high)/2;
+      odd  = (*low + *high)/2;
+
+      if (even > 1023) even = 1023;
+      if (even < 0) even = 0;
+      if (odd > 1023) odd = 1023;
+      if (odd < 0) odd = 0;
+
+      output[i] = even;
+      output[i + linesize] = odd;
+      low++;
+      high++;
+    }
+}
 static void horiz_filter(int16_t *output, int16_t *low, int16_t *high,
                          int width)
 {
@@ -277,6 +303,9 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
         uint16_t data   = bytestream2_get_be16(&gb);
         if (abs_tag8 >= 0x60 && abs_tag8 <= 0x6f) {
             av_log(avctx, AV_LOG_DEBUG, "large len %x\n", ((tagu & 0xff) << 16) | data);
+        } else if (tag == Progressive) {
+            av_log(avctx, AV_LOG_DEBUG, "Progressive?%"PRIu16"\n", data);
+            s->progressive = data;
         } else if (tag == ImageWidth) {
             av_log(avctx, AV_LOG_DEBUG, "Width %"PRIu16"\n", data);
             s->coded_width = data;
@@ -766,36 +795,71 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
         }
 
         av_log(avctx, AV_LOG_DEBUG, "Level 3 plane %i %i %i %i\n", plane, lowpass_height, lowpass_width, highpass_stride);
-
+        if (s->progressive) {
+          low    = s->plane[plane].subband[0];
+          high   = s->plane[plane].subband[8];
+          output = s->plane[plane].l_h[6];
+          for (i = 0; i < lowpass_width; i++) {
+              vert_filter(output, lowpass_width, low, lowpass_width, high, highpass_stride, lowpass_height);
+              low++;
+              high++;
+              output++;
+          }
+
+          low    = s->plane[plane].subband[7];
+          high   = s->plane[plane].subband[9];
+          output = s->plane[plane].l_h[7];
+          for (i = 0; i < lowpass_width; i++) {
+              vert_filter(output, lowpass_width, low, highpass_stride, high, highpass_stride, lowpass_height);
+              low++;
+              high++;
+              output++;
+          }
+
+          dst = (int16_t *)pic->data[act_plane];
+          low  = s->plane[plane].l_h[6];
+          high = s->plane[plane].l_h[7];
+          for (i = 0; i < lowpass_height * 2; i++) {
+              horiz_filter_clip(dst, low, high, lowpass_width, s->bpc);
+              low  += lowpass_width;
+              high += lowpass_width;
+              dst  += pic->linesize[act_plane] / 2;
+          }
+      }
+      else {
+
+        av_log(avctx, AV_LOG_DEBUG, "interlaced frame ? %d", pic->interlaced_frame);
+        pic->interlaced_frame = 1;
         low    = s->plane[plane].subband[0];
-        high   = s->plane[plane].subband[8];
+        high   = s->plane[plane].subband[7];
         output = s->plane[plane].l_h[6];
-        for (i = 0; i < lowpass_width; i++) {
-            vert_filter(output, lowpass_width, low, lowpass_width, high, highpass_stride, lowpass_height);
-            low++;
-            high++;
-            output++;
+        for (i = 0; i < lowpass_height; i++) {
+            horiz_filter(output, low, high, lowpass_width);
+            low    += lowpass_width;
+            high   += lowpass_width;
+            output += lowpass_width * 2;
         }
 
-        low    = s->plane[plane].subband[7];
+        low    = s->plane[plane].subband[8];
         high   = s->plane[plane].subband[9];
         output = s->plane[plane].l_h[7];
-        for (i = 0; i < lowpass_width; i++) {
-            vert_filter(output, lowpass_width, low, highpass_stride, high, highpass_stride, lowpass_height);
-            low++;
-            high++;
-            output++;
+        for (i = 0; i < lowpass_height; i++) {
+            horiz_filter(output, low, high, lowpass_width);
+            low    += lowpass_width;
+            high   += lowpass_width;
+            output += lowpass_width * 2;
         }
 
-        dst = (int16_t *)pic->data[act_plane];
+        dst  = (int16_t *)pic->data[act_plane];
         low  = s->plane[plane].l_h[6];
         high = s->plane[plane].l_h[7];
-        for (i = 0; i < lowpass_height * 2; i++) {
-            horiz_filter_clip(dst, low, high, lowpass_width, s->bpc);
-            low  += lowpass_width;
-            high += lowpass_width;
-            dst  += pic->linesize[act_plane] / 2;
+       for (i = 0; i < lowpass_height; i++) {
+            interlaced_vertical_filter(dst, low, high, lowpass_width * 2,  pic->linesize[act_plane]/2, act_plane);
+            low  += lowpass_width * 2;
+            high += lowpass_width * 2;
+            dst  += pic->linesize[act_plane];
         }
+      }
     }
 
 
diff --git a/libavcodec/cfhd.h b/libavcodec/cfhd.h
index 2573e750a6..f9e1c60c3b 100644
--- a/libavcodec/cfhd.h
+++ b/libavcodec/cfhd.h
@@ -83,7 +83,8 @@ typedef struct CFHDContext {
     int coded_height;
     int cropped_height;
     enum AVPixelFormat coded_format;
-
+    int progressive;
+    
     int a_width;
     int a_height;
     int a_format;