[FFmpeg-cvslog] pngdec: 4bpp support

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Tue Sep  6 13:35:15 2011 +0200| [738219c921d6037f8acfcde1c567c3b16fb625fe] | committer: Michael Niedermayer

pngdec: 4bpp support
Fixes Ticket208

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=738219c921d6037f8acfcde1c567c3b16fb625fe
---

 libavcodec/pngdec.c |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 7063567..0b6a62d 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -27,7 +27,7 @@
 #include "png.h"
 
 /* TODO:
- * - add 2, 4 and 16 bit depth support
+ * - add 2 and 16 bit depth support
  */
 
 #include <zlib.h>
@@ -580,6 +580,19 @@ static int decode_frame(AVCodecContext *avctx,
         }
     }
  exit_loop:
+
+    if(s->bits_per_pixel == 4){
+        int i, j;
+        uint8_t *pd = s->current_picture->data[0];
+        for(j=0; j < s->height; j++) {
+            for(i=s->width/2-1; i>=0; i--) {
+                pd[2*i+1]= pd[i]&15;
+                pd[2*i+0]= pd[i]>>4;
+            }
+            pd += s->image_linesize;
+        }
+    }
+
      /* handle p-frames only if a predecessor frame is available */
      if(s->last_picture->data[0] != NULL) {
          if(!(avpkt->flags & AV_PKT_FLAG_KEY)) {