Split cabac decoding code out of h264.c.

not slower according to benchmarks.

Originally committed as revision 21181 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/Makefile

@@ -132,7 +132,7 @@ OBJS-$(CONFIG_H263_ENCODER)            += mpegvideo_enc.o mpeg4video.o mpeg4vide
                                           ratecontrol.o h263.o ituh263enc.o flvenc.o mpeg12data.o \
                                           mpegvideo.o error_resilience.o
 OBJS-$(CONFIG_H264_DECODER)            += h264.o h264idct.o h264pred.o h264_loopfilter.o h264_direct.o cabac.o \
-                                          h264_sei.o h264_ps.o h264_refs.o h264_cavlc.o\
+                                          h264_sei.o h264_ps.o h264_refs.o h264_cavlc.o h264_cabac.o\
                                           mpegvideo.o error_resilience.o
 OBJS-$(CONFIG_H264_ENCODER)            += h264enc.o h264dspenc.o
 OBJS-$(CONFIG_H264_VAAPI_HWACCEL)      += vaapi_h264.o
@@ -283,7 +283,7 @@ OBJS-$(CONFIG_SVQ1_ENCODER)            += svq1enc.o svq1.o    \
                                           motion_est.o h263.o \
                                           mpegvideo.o error_resilience.o
 OBJS-$(CONFIG_SVQ3_DECODER)            += h264.o svq3.o h264idct.o h264pred.o h264_loopfilter.o h264_direct.o  \
-                                          h264_sei.o h264_ps.o h264_refs.o h264_cavlc.o\
+                                          h264_sei.o h264_ps.o h264_refs.o h264_cavlc.o h264_cabac.o \
                                           cabac.o          \
                                           mpegvideo.o error_resilience.o \
                                           svq1dec.o svq1.o h263.o

libavcodec/h264.h

@@ -651,6 +651,14 @@ av_cold void ff_h264_decode_init_vlc(void);
  */
 int ff_h264_decode_mb_cavlc(H264Context *h);
 
+/**
+ * decodes a CABAC coded macroblock
+ * @returns 0 if OK, AC_ERROR / DC_ERROR / MV_ERROR if an error is noticed
+ */
+int ff_h264_decode_mb_cabac(H264Context *h);
+
+void ff_h264_init_cabac_states(H264Context *h);
+
 void ff_h264_direct_dist_scale_factor(H264Context * const h);
 void ff_h264_direct_ref_list_init(H264Context * const h);
 void ff_h264_pred_direct_motion(H264Context * const h, int *mb_type);