[FFmpeg-cvslog] h264_mp4toannexb: Switch to GetByteContext to read extradata
Andreas Rheinhardt
git at videolan.org
Fri Mar 6 02:00:00 EET 2020
ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Sat Dec 14 23:19:15 2019 +0100| [0ccb31f1356ed306febd74cb6d691017f20a1891] | committer: Michael Niedermayer
h264_mp4toannexb: Switch to GetByteContext to read extradata
This is done in order to improve readability. No functional change is
intended with this commit at all; in particular, the unsafe read
functions are used throughout as h264_extradata_to_annexb already
performs its own checks. (These checks will nevertheless be improved
in further commits.)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0ccb31f1356ed306febd74cb6d691017f20a1891
---
libavcodec/h264_mp4toannexb_bsf.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/libavcodec/h264_mp4toannexb_bsf.c b/libavcodec/h264_mp4toannexb_bsf.c
index bbf124ad04..f31902b506 100644
--- a/libavcodec/h264_mp4toannexb_bsf.c
+++ b/libavcodec/h264_mp4toannexb_bsf.c
@@ -27,6 +27,7 @@
#include "avcodec.h"
#include "bsf.h"
+#include "bytestream.h"
#include "h264.h"
typedef struct H264BSFContext {
@@ -68,18 +69,25 @@ static int alloc_and_copy(AVPacket *out,
static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding)
{
H264BSFContext *s = ctx->priv_data;
+ GetByteContext ogb, *gb = &ogb;
uint16_t unit_size;
uint32_t total_size = 0;
uint8_t *out = NULL, unit_nb, sps_done = 0,
sps_seen = 0, pps_seen = 0;
- const uint8_t *extradata = ctx->par_in->extradata + 4;
static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
- int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
+ int length_size;
s->sps_offset = s->pps_offset = -1;
+ bytestream2_init(gb, ctx->par_in->extradata, ctx->par_in->extradata_size);
+
+ bytestream2_skipu(gb, 4);
+
+ /* retrieve length coded size */
+ length_size = (bytestream2_get_byteu(gb) & 0x3) + 1;
+
/* retrieve sps and pps unit(s) */
- unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
+ unit_nb = bytestream2_get_byteu(gb) & 0x1f; /* number of sps unit(s) */
if (!unit_nb) {
goto pps;
} else {
@@ -90,10 +98,10 @@ static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding)
while (unit_nb--) {
int err;
- unit_size = AV_RB16(extradata);
+ unit_size = bytestream2_get_be16u(gb);
total_size += unit_size + 4;
av_assert1(total_size <= INT_MAX - padding);
- if (extradata + 2 + unit_size > ctx->par_in->extradata + ctx->par_in->extradata_size) {
+ if (gb->buffer + unit_size > gb->buffer_end) {
av_log(ctx, AV_LOG_ERROR, "Packet header is not contained in global extradata, "
"corrupted stream or invalid MP4/AVCC bitstream\n");
av_free(out);
@@ -102,11 +110,10 @@ static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding)
if ((err = av_reallocp(&out, total_size + padding)) < 0)
return err;
memcpy(out + total_size - unit_size - 4, nalu_header, 4);
- memcpy(out + total_size - unit_size, extradata + 2, unit_size);
- extradata += 2 + unit_size;
+ bytestream2_get_bufferu(gb, out + total_size - unit_size, unit_size);
pps:
if (!unit_nb && !sps_done++) {
- unit_nb = *extradata++; /* number of pps unit(s) */
+ unit_nb = bytestream2_get_byteu(gb); /* number of pps unit(s) */
if (unit_nb) {
s->pps_offset = total_size;
pps_seen = 1;
More information about the ffmpeg-cvslog
mailing list