aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorAnton Khirnov <anton@khirnov.net>2016-03-21 12:42:12 +0100
committerAnton Khirnov <anton@khirnov.net>2016-03-28 09:47:25 +0200
commit90ed6c5cf7f236bc9efb47c97b40358c666d1386 (patch)
tree102c7499ceb66eefccfc28a978ee7c51692882f2
parentb667252a41fbf5a3f6ea8c67fdbc03db3d748977 (diff)
downloadffmpeg-90ed6c5cf7f236bc9efb47c97b40358c666d1386.tar.gz
h2645_parse: compute the actual data length, without trailing paddding
This is required by h264.
-rw-r--r--libavcodec/h2645_parse.c39
-rw-r--r--libavcodec/h2645_parse.h6
2 files changed, 42 insertions, 3 deletions
diff --git a/libavcodec/h2645_parse.c b/libavcodec/h2645_parse.c
index 310b0093ca..defe001de7 100644
--- a/libavcodec/h2645_parse.c
+++ b/libavcodec/h2645_parse.c
@@ -22,13 +22,12 @@
#include "config.h"
+#include "libavutil/intmath.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/mem.h"
#include "h2645_parse.h"
-/* FIXME: This is adapted from ff_h264_decode_nal, avoiding duplication
- * between these functions would be nice. */
int ff_h2645_extract_rbsp(const uint8_t *src, int length,
H2645NAL *nal)
{
@@ -128,6 +127,31 @@ nsc:
return si;
}
+static int get_bit_length(H2645NAL *nal, int skip_trailing_zeros)
+{
+ int size = nal->size;
+ int v;
+
+ while (skip_trailing_zeros && size > 0 && nal->data[size - 1] == 0)
+ size--;
+
+ if (!size)
+ return 0;
+
+ v = nal->data[size - 1];
+
+ if (size > INT_MAX / 8)
+ return AVERROR(ERANGE);
+ size *= 8;
+
+ /* remove the stop bit and following trailing zeros,
+ * or nothing for damaged bitstreams */
+ if (v)
+ size -= av_ctz(v) + 1;
+
+ return size;
+}
+
/**
* @return AVERROR_INVALIDDATA if the packet is not a valid NAL unit,
* 0 if the unit should be skipped, 1 otherwise
@@ -181,6 +205,7 @@ int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
while (length >= 4) {
H2645NAL *nal;
int extract_length = 0;
+ int skip_trailing_zeros = 1;
if (is_nalff) {
int i;
@@ -224,7 +249,15 @@ int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
if (consumed < 0)
return consumed;
- ret = init_get_bits8(&nal->gb, nal->data, nal->size);
+ /* see commit 3566042a0 */
+ if (consumed < length - 3 &&
+ buf[consumed] == 0x00 && buf[consumed + 1] == 0x00 &&
+ buf[consumed + 2] == 0x01 && buf[consumed + 3] == 0xE0)
+ skip_trailing_zeros = 0;
+
+ nal->size_bits = get_bit_length(nal, skip_trailing_zeros);
+
+ ret = init_get_bits(&nal->gb, nal->data, nal->size_bits);
if (ret < 0)
return ret;
diff --git a/libavcodec/h2645_parse.h b/libavcodec/h2645_parse.h
index 148ccf30ac..651cf26795 100644
--- a/libavcodec/h2645_parse.h
+++ b/libavcodec/h2645_parse.h
@@ -33,6 +33,12 @@ typedef struct H2645NAL {
int size;
const uint8_t *data;
+ /**
+ * Size, in bits, of just the data, excluding the stop bit and any trailing
+ * padding. I.e. what HEVC calls SODB.
+ */
+ int size_bits;
+
int raw_size;
const uint8_t *raw_data;