diff options
| author | James Almer <jamrial@gmail.com> | 2022-10-20 23:54:14 -0300 |
|---|---|---|
| committer | James Almer <jamrial@gmail.com> | 2022-10-26 09:16:21 -0300 |
| commit | 72db6a4f5f5a909114ad46f5c5fb1221f452e9f3 (patch) | |
| tree | ec959be68d5a2ab8284082d558fda5531b2ec17e /libavcodec | |
| parent | 31162eb9490e51a526ff0f78a57303a4d6433aba (diff) | |
| download | ffmpeg-72db6a4f5f5a909114ad46f5c5fb1221f452e9f3.tar.gz | |
avcodec/ac3dec: split off code discarding garbage at the beginning of a packet
Signed-off-by: James Almer <jamrial@gmail.com>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/ac3_parser.c | 19 | ||||
| -rw-r--r-- | libavcodec/ac3_parser_internal.h | 2 | ||||
| -rw-r--r-- | libavcodec/ac3dec.c | 15 |
3 files changed, 23 insertions, 13 deletions
diff --git a/libavcodec/ac3_parser.c b/libavcodec/ac3_parser.c index 4f154bb7c4..425e1b4742 100644 --- a/libavcodec/ac3_parser.c +++ b/libavcodec/ac3_parser.c @@ -53,6 +53,25 @@ static const uint8_t center_levels[4] = { 4, 5, 6, 5 }; */ static const uint8_t surround_levels[4] = { 4, 6, 7, 6 }; +int ff_ac3_find_syncword(const uint8_t *buf, int buf_size) +{ + int i; + + for (i = 1; i < buf_size; i += 2) { + if (buf[i] == 0x77 || buf[i] == 0x0B) { + if ((buf[i] ^ buf[i-1]) == (0x77 ^ 0x0B)) { + i--; + break; + } else if ((buf[i] ^ buf[i+1]) == (0x77 ^ 0x0B)) { + break; + } + } + } + if (i >= buf_size) + return AVERROR_INVALIDDATA; + + return i; +} int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr) { diff --git a/libavcodec/ac3_parser_internal.h b/libavcodec/ac3_parser_internal.h index bd4e1bbffb..2ac0e67ec2 100644 --- a/libavcodec/ac3_parser_internal.h +++ b/libavcodec/ac3_parser_internal.h @@ -79,4 +79,6 @@ int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr); int avpriv_ac3_parse_header(AC3HeaderInfo **hdr, const uint8_t *buf, size_t size); +int ff_ac3_find_syncword(const uint8_t *buf, int buf_size); + #endif /* AVCODEC_AC3_PARSER_INTERNAL_H */ diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c index 340f6e1e37..8e40587ff1 100644 --- a/libavcodec/ac3dec.c +++ b/libavcodec/ac3dec.c @@ -1508,19 +1508,8 @@ static int ac3_decode_frame(AVCodecContext *avctx, AVFrame *frame, s->superframe_size = 0; buf_size = full_buf_size; - for (i = 1; i < buf_size; i += 2) { - if (buf[i] == 0x77 || buf[i] == 0x0B) { - if ((buf[i] ^ buf[i-1]) == (0x77 ^ 0x0B)) { - i--; - break; - } else if ((buf[i] ^ buf[i+1]) == (0x77 ^ 0x0B)) { - break; - } - } - } - if (i >= buf_size) - return AVERROR_INVALIDDATA; - if (i > 10) + i = ff_ac3_find_syncword(buf, buf_size); + if (i < 0 || i > 10) return i; buf += i; buf_size -= i; |