Signed-off-by: jianfeng.zheng <jianfeng.zh...@mthreads.com>
---
libavcodec/cavs.h | 2 +
libavcodec/cavsdec.c | 87 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 89 insertions(+)
diff --git a/libavcodec/cavs.h b/libavcodec/cavs.h
index 244c322b35..ad49abff92 100644
--- a/libavcodec/cavs.h
+++ b/libavcodec/cavs.h
@@ -39,8 +39,10 @@
#define EXT_START_CODE 0x000001b5
#define USER_START_CODE 0x000001b2
#define CAVS_START_CODE 0x000001b0
+#define VIDEO_SEQ_END_CODE 0x000001b1
#define PIC_I_START_CODE 0x000001b3
#define PIC_PB_START_CODE 0x000001b6
+#define VIDEO_EDIT_CODE 0x000001b7
#define A_AVAIL 1
#define B_AVAIL 2
diff --git a/libavcodec/cavsdec.c b/libavcodec/cavsdec.c
index b356da0b04..9742bd1011 100644
--- a/libavcodec/cavsdec.c
+++ b/libavcodec/cavsdec.c
@@ -954,6 +954,80 @@ static inline int decode_slice_header(AVSContext *h,
GetBitContext *gb)
return 0;
}
+/**
+ * skip stuffing bits before next start code "0x000001"
+ * @return '0' no stuffing bits placed at h->gb being skip, else '1'.
+ */
+static inline int skip_stuffing_bits(AVSContext *h)
+{
+ GetBitContext gb0 = h->gb;
+ GetBitContext *gb = &h->gb;
+ const uint8_t *start;
+ const uint8_t *ptr;
+ const uint8_t *end;
+ int align;
+ int stuffing_zeros;
+
+ /**
+ * According to spec, there should be one stuffing_bit '1' and
+ * 0~7 stuffing_bit '0'. But seems not all the stream follow
+ * "next_start_code()" strictly.
+ */
+ align = (-get_bits_count(gb)) & 7;
+ if (align == 0 && show_bits_long(gb, 8) == 0x80) {
+ skip_bits_long(gb, 8);
+ }
+
+ /**
+ * skip leading zero bytes before 0x 00 00 01 stc
+ */
+ ptr = start = align_get_bits(gb);
+ end = gb->buffer_end;
+ while (ptr < end && *ptr == 0)
+ ptr++;
+
+ if ((ptr >= end) || (*ptr == 1 && ptr - start >= 2)) {
+ stuffing_zeros = (ptr >= end ? end - start : ptr - start - 2);
+ if (stuffing_zeros > 0)
+ av_log(h->avctx, AV_LOG_DEBUG, "Skip 0x%x stuffing zeros @0x%x.\n",
+ stuffing_zeros, (int)(start - gb->buffer));
+ skip_bits_long(gb, stuffing_zeros * 8);
+ return 1;
+ } else {
+ av_log(h->avctx, AV_LOG_DEBUG, "No next_start_code() found @0x%x.\n",
+ (int)(start - gb->buffer));
+ goto restore_get_bits;
+ }
+
+restore_get_bits:
+ h->gb = gb0;
+ return 0;
+}
+
+static inline int skip_extension_and_user_data(AVSContext *h)
+{
+ int stc = -1;
+ const uint8_t *start = align_get_bits(&h->gb);
+ const uint8_t *end = h->gb.buffer_end;
+ const uint8_t *ptr, *next;
+
+ for (ptr = start; ptr + 4 < end; ptr = next) {
+ stc = show_bits_long(&h->gb, 32);
+ if (stc != EXT_START_CODE && stc != USER_START_CODE) {
+ break;
+ }
+ next = avpriv_find_start_code(ptr + 4, end, &stc);
+ if (next < end) {
+ next -= 4;
+ }
+ skip_bits(&h->gb, (next - ptr) * 8);
+ av_log(h->avctx, AV_LOG_DEBUG, "skip %d byte ext/user data\n",
+ (int)(next - ptr));
+ }
+
+ return ptr > start;
+}
+
static inline int check_for_slice(AVSContext *h)
{
GetBitContext *gb = &h->gb;
@@ -1019,6 +1093,8 @@ static int decode_pic(AVSContext *h)
h->stream_revision = 1;
if (h->stream_revision > 0)
skip_bits(&h->gb, 1); //marker_bit
+
+ av_log(h->avctx, AV_LOG_DEBUG, "stream_revision: %d\n",
h->stream_revision);
}
if (get_bits_left(&h->gb) < 23)
@@ -1096,6 +1172,11 @@ static int decode_pic(AVSContext *h)
h->alpha_offset = h->beta_offset = 0;
}
+ if (h->stream_revision > 0) {
+ skip_stuffing_bits(h);
+ skip_extension_and_user_data(h);
+ }
+
ret = 0;
if (h->cur.f->pict_type == AV_PICTURE_TYPE_I) {
do {
@@ -1309,6 +1390,12 @@ static int cavs_decode_frame(AVCodecContext *avctx,
AVFrame *rframe,
case USER_START_CODE:
//mpeg_decode_user_data(avctx, buf_ptr, input_size);
break;
+ case VIDEO_EDIT_CODE:
+ av_log(h->avctx, AV_LOG_WARNING, "Skip video_edit_code\n");
+ break;
+ case VIDEO_SEQ_END_CODE:
+ av_log(h->avctx, AV_LOG_WARNING, "Skip video_sequence_end_code\n");
+ break;
default:
if (stc <= SLICE_MAX_START_CODE) {
init_get_bits(&h->gb, buf_ptr, input_size);
--
2.25.1
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