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avcodec: h264: Extract decoder methods 

Extract two methods from decode_registered_user_data in order to improve
code readability. Also make the constant holding the allocation size a
64-bit unsigned integer so that the size comparison against INT_MAX makes
sense.

Bug-Id: CID1312090

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
This commit is contained in:
David Holm 2015-07-31 21:06:13 +02:00 committed by Luca Barbato
parent 33dc1913ab
commit 80ea661128
1 changed files with 70 additions and 54 deletions
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124
libavcodec/h264_sei.c
View File

@ -106,11 +106,78 @@ static int decode_picture_timing(H264Context *h)
return 0;
}
static int decode_registered_user_data_afd(H264Context *h, int size)
{
int flag;
if (size-- < 1)
return AVERROR_INVALIDDATA;
skip_bits(&h->gb, 1); // 0
flag = get_bits(&h->gb, 1); // active_format_flag
skip_bits(&h->gb, 6); // reserved
if (flag) {
if (size-- < 1)
return AVERROR_INVALIDDATA;
skip_bits(&h->gb, 4); // reserved
h->active_format_description = get_bits(&h->gb, 4);
h->sei_reguserdata_afd_present = 1;
}
return 0;
}
static int decode_registered_user_data_closed_caption(H264Context *h, int size)
{
int flag;
int user_data_type_code;
int cc_count;
if (size < 3)
return AVERROR(EINVAL);
user_data_type_code = get_bits(&h->gb, 8);
if (user_data_type_code == 0x3) {
skip_bits(&h->gb, 1); // reserved
flag = get_bits(&h->gb, 1); // process_cc_data_flag
if (flag) {
skip_bits(&h->gb, 1); // zero bit
cc_count = get_bits(&h->gb, 5);
skip_bits(&h->gb, 8); // reserved
size -= 2;
if (cc_count && size >= cc_count * 3) {
const uint64_t new_size = (h->a53_caption_size + cc_count
* UINT64_C(3));
int i, ret;
if (new_size > INT_MAX)
return AVERROR(EINVAL);
/* Allow merging of the cc data from two fields. */
ret = av_reallocp(&h->a53_caption, new_size);
if (ret < 0)
return ret;
for (i = 0; i < cc_count; i++) {
h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8);
h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8);
h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8);
}
skip_bits(&h->gb, 8); // marker_bits
}
}
}
return 0;
}
static int decode_registered_user_data(H264Context *h, int size)
{
uint32_t country_code;
uint32_t user_identifier;
int flag, user_data_type_code, cc_count;
if (size < 7)
return AVERROR_INVALIDDATA;
@ -129,60 +196,9 @@ static int decode_registered_user_data(H264Context *h, int size)
switch (user_identifier) {
case MKBETAG('D', 'T', 'G', '1'): // afd_data
if (size-- < 1)
return AVERROR_INVALIDDATA;
skip_bits(&h->gb, 1); // 0
flag = get_bits(&h->gb, 1); // active_format_flag
skip_bits(&h->gb, 6); // reserved
if (flag) {
if (size-- < 1)
return AVERROR_INVALIDDATA;
skip_bits(&h->gb, 4); // reserved
h->active_format_description = get_bits(&h->gb, 4);
h->sei_reguserdata_afd_present = 1;
}
break;
return decode_registered_user_data_afd(h, size);
case MKBETAG('G', 'A', '9', '4'): // closed captions
if (size < 3)
return AVERROR(EINVAL);
user_data_type_code = get_bits(&h->gb, 8);
if (user_data_type_code == 0x3) {
skip_bits(&h->gb, 1); // reserved
flag = get_bits(&h->gb, 1); // process_cc_data_flag
if (flag) {
skip_bits(&h->gb, 1); // zero bit
cc_count = get_bits(&h->gb, 5);
skip_bits(&h->gb, 8); // reserved
size -= 2;
if (cc_count && size >= cc_count * 3) {
int i, ret;
int new_size = (int64_t) h->a53_caption_size +
(int64_t) cc_count * 3;
if (new_size > INT_MAX)
return AVERROR(EINVAL);
/* Allow merging of the cc data from two fields. */
ret = av_reallocp(&h->a53_caption,
h->a53_caption_size + cc_count * 3);
if (ret < 0)
return ret;
for (i = 0; i < cc_count; i++) {
h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8);
h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8);
h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8);
}
skip_bits(&h->gb, 8); // marker_bits
}
}
}
break;
return decode_registered_user_data_closed_caption(h, size);
default:
skip_bits(&h->gb, size * 8);
break;