avcodec/hevc_parser: fix missing zero_byte at frame beginning

The start code is matched against 0x000001, zero_byte was treated
as last byte of last frame rather than the beginning of next frame.

Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>

libavcodec/hevc_parser.c

@@ -278,6 +278,8 @@ static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf,
             (nut >= 41 && nut <= 44) || (nut >= 48 && nut <= 55)) {
             if (pc->frame_start_found) {
                 pc->frame_start_found = 0;
+                if (!((pc->state64 >> 6 * 8) & 0xFF))
+                    return i - 6;
                 return i - 5;
             }
         } else if (nut <= HEVC_NAL_RASL_R ||
@@ -288,6 +290,8 @@ static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf,
                     pc->frame_start_found = 1;
                 } else { // First slice of next frame found
                     pc->frame_start_found = 0;
+                    if (!((pc->state64 >> 6 * 8) & 0xFF))
+                        return i - 6;
                     return i - 5;
                 }
             }

tests/fate/hevc.mak

@@ -222,7 +222,7 @@ FATE_HEVC-$(call ALLYES, HEVC_DEMUXER MOV_DEMUXER HEVC_PARSER HEVC_MP4TOANNEXB_B
 fate-hevc-bsf-mp4toannexb: tests/data/hevc-mp4.mov
 fate-hevc-bsf-mp4toannexb: CMD = md5 -i $(TARGET_PATH)/tests/data/hevc-mp4.mov -c:v copy -fflags +bitexact -f hevc
 fate-hevc-bsf-mp4toannexb: CMP = oneline
-fate-hevc-bsf-mp4toannexb: REF = 1873662a3af1848c37e4eb25722c8df9
+fate-hevc-bsf-mp4toannexb: REF = 73019329ed7f81c24f9af67c34c640c0
 
 fate-hevc-skiploopfilter: CMD = framemd5 -skip_loop_filter nokey -i $(TARGET_SAMPLES)/hevc-conformance/SAO_D_Samsung_5.bit -sws_flags bitexact
 FATE_HEVC-$(call FRAMEMD5, HEVC, HEVC, HEVC_PARSER) += fate-hevc-skiploopfilter