[FFmpeg-devel] [PATCH] PB-frames support for i263

[Kostya]

On Thu, Feb 19, 2009 at 01:59:37PM +0100, Michael Niedermayer wrote:
> On Thu, Feb 19, 2009 at 09:27:21AM +0200, Kostya wrote:
[...] 
> > Index: libavcodec/h263.c
> > ===================================================================
> > --- libavcodec/h263.c	(revision 16921)
> > +++ libavcodec/h263.c	(working copy)
> > @@ -6185,17 +6232,48 @@
> >          return -1;      /* SAC: off */
> >      }
> >      s->obmc= get_bits1(&s->gb);
> > -    if (get_bits1(&s->gb) != 0) {
> > -        av_log(s->avctx, AV_LOG_ERROR, "PB frame mode no supported\n");
> > -        return -1;      /* PB frame mode */
> > +    s->pb_frame = get_bits1(&s->gb);
> > +
> > +    if(format == 7){
> > +        format = get_bits(&s->gb, 3);
> > +        if(format == 0 || format == 7){
> > +            av_log(s->avctx, AV_LOG_ERROR, "Wrong Intel H263 format\n");
> > +            return -1;
> > +        }
> > +        if(get_bits(&s->gb, 2))
> > +            av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
> > +        s->loop_filter = get_bits1(&s->gb);
> 
> > +        if(get_bits1(&s->gb)){
> > +            av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
> > +            return -1;
> > +        }
> 
> hmm

oops

> > +        if(get_bits1(&s->gb))
> > +            s->pb_frame = 2;
> > +        if(get_bits(&s->gb, 5))
> > +            av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
> > +        if(get_bits(&s->gb, 5) != 1)
> > +            av_log(s->avctx, AV_LOG_ERROR, "Invalid marker\n");
> >      }
> > +    if(format == 6){
> > +        int ar = get_bits(&s->gb, 4);
> > +        skip_bits(&s->gb, 9); // display width
> 
> > +        if(!get_bits1(&s->gb))
> > +            return -1;
> 
> hmpf
 
 
oops2

This one should be right.
In unrelated news - H.263 improved PB frames (annex M) use VLC for pb_mv_count
(0, 10, ..., 11110, 11111) so I have to change code in ff_h263_decode_mb() for
full H.263 PB-frame support, not only i263.
 
> [...]
> -- 
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
-------------- next part --------------
Index: libavcodec/h263.c
===================================================================
--- libavcodec/h263.c	(revision 16921)
+++ libavcodec/h263.c	(working copy)
@@ -6185,17 +6237,45 @@
         return -1;      /* SAC: off */
     }
     s->obmc= get_bits1(&s->gb);
-    if (get_bits1(&s->gb) != 0) {
-        av_log(s->avctx, AV_LOG_ERROR, "PB frame mode no supported\n");
-        return -1;      /* PB frame mode */
+    s->pb_frame = get_bits1(&s->gb);
+
+    if(format == 7){
+        format = get_bits(&s->gb, 3);
+        if(format == 0 || format == 7){
+            av_log(s->avctx, AV_LOG_ERROR, "Wrong Intel H263 format\n");
+            return -1;
+        }
+        if(get_bits(&s->gb, 2))
+            av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
+        s->loop_filter = get_bits1(&s->gb);
+        if(get_bits1(&s->gb))
+            av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
+        if(get_bits1(&s->gb))
+            s->pb_frame = 2;
+        if(get_bits(&s->gb, 5))
+            av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
+        if(get_bits(&s->gb, 5) != 1)
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid marker\n");
     }
+    if(format == 6){
+        int ar = get_bits(&s->gb, 4);
+        skip_bits(&s->gb, 9); // display width
+        skip_bits1(&s->gb);
+        skip_bits(&s->gb, 9); // display height
+        if(ar == 15){
+            skip_bits(&s->gb, 8); // aspect ratio - width
+            skip_bits(&s->gb, 8); // aspect ratio - height
+        }
+    }
 
-    /* skip unknown header garbage */
-    skip_bits(&s->gb, 41);
-
     s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
     skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
 
+    if(s->pb_frame){
+        skip_bits(&s->gb, 3); //temporal reference for B-frame
+        skip_bits(&s->gb, 2); //dbquant
+    }
+
     /* PEI */
     while (get_bits1(&s->gb) != 0) {
         skip_bits(&s->gb, 8);
@@ -6208,6 +6288,10 @@
     if(s->avctx->debug&FF_DEBUG_PICT_INFO)
         show_pict_info(s);
 
+    if(s->pb_frame){
+        av_log(s->avctx, AV_LOG_ERROR, "PB frame mode no supported\n");
+        return -1;      /* PB frame mode */
+    }
     return 0;
 }
 
Index: libavcodec/mpegvideo.h
===================================================================
--- libavcodec/mpegvideo.h	(revision 16921)
+++ libavcodec/mpegvideo.h	(working copy)
@@ -201,6 +201,7 @@
     int bit_rate;     ///< wanted bit rate
     enum OutputFormat out_format; ///< output format
     int h263_pred;    ///< use mpeg4/h263 ac/dc predictions
+    int pb_frame;     ///< PB frame mode (0 = none, 1 = base, 2 = improved)
 
 /* the following codec id fields are deprecated in favor of codec_id */
     int h263_plus;    ///< h263 plus headers