avcodec/vp5/6/8: use vpX_rac_is_end()

Reviewed-by: Peter Ross <pross@xvid.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit ab56e62e8f)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 1dd89192c5)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/vp5.c

@@ -183,7 +183,7 @@ static int vp5_parse_coeff(VP56Context *s)
     int b, i, cg, idx, ctx, ctx_last;
     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
 
-    if (c->end <= c->buffer && c->bits >= 0) {
+    if (vpX_rac_is_end(c)) {
         av_log(s->avctx, AV_LOG_ERROR, "End of AC stream reached in vp5_parse_coeff\n");
         return AVERROR_INVALIDDATA;
     }

libavcodec/vp6.c

@@ -460,7 +460,7 @@ static int vp6_parse_coeff(VP56Context *s)
     int b, i, cg, idx, ctx;
     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
 
-    if (c->end <= c->buffer && c->bits >= 0) {
+    if (vpX_rac_is_end(c)) {
         av_log(s->avctx, AV_LOG_ERROR, "End of AC stream reached in vp6_parse_coeff\n");
         return AVERROR_INVALIDDATA;
     }

libavcodec/vp8.c

@@ -606,7 +606,7 @@ static int vp7_decode_frame_header(VP8Context *s, const uint8_t *buf, int buf_si
             s->fade_present = vp8_rac_get(c);
     }
 
-    if (c->end <= c->buffer && c->bits >= 0)
+    if (vpX_rac_is_end(c))
         return AVERROR_INVALIDDATA;
     /* E. Fading information for previous frame */
     if (s->fade_present && vp8_rac_get(c)) {
@@ -2301,7 +2301,7 @@ static av_always_inline int decode_mb_row_no_filter(AVCodecContext *avctx, void
         curframe->tf.f->data[2] +  8 * mb_y * s->uvlinesize
     };
 
-    if (c->end <= c->buffer && c->bits >= 0)
+    if (vpX_rac_is_end(c))
          return AVERROR_INVALIDDATA;
 
     if (mb_y == 0)
@@ -2332,7 +2332,7 @@ static av_always_inline int decode_mb_row_no_filter(AVCodecContext *avctx, void
     s->mv_max.x = ((s->mb_width - 1) << 6) + MARGIN;
 
     for (mb_x = 0; mb_x < s->mb_width; mb_x++, mb_xy++, mb++) {
-        if (c->end <= c->buffer && c->bits >= 0)
+        if (vpX_rac_is_end(c))
             return AVERROR_INVALIDDATA;
         // Wait for previous thread to read mb_x+2, and reach mb_y-1.
         if (prev_td != td) {