From 083cbc930d077651ea7e3fbc32ec45352cfed7e7 Mon Sep 17 00:00:00 2001 From: Tom Butterworth Date: Tue, 21 Jul 2015 01:21:38 +0100 Subject: snappy: Refactor so ff_snappy_uncompress() uses an existing buffer Some uses of Snappy require uncompressing to positions within an existing buffer. Also adds a function to get the uncompressed length of Snappy data. --- libavcodec/snappy.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) (limited to 'libavcodec/snappy.c') diff --git a/libavcodec/snappy.c b/libavcodec/snappy.c index 13ef1ec137..df6c6b386a 100644 --- a/libavcodec/snappy.c +++ b/libavcodec/snappy.c @@ -128,7 +128,17 @@ static int64_t decode_len(GetByteContext *gb) return len; } -int ff_snappy_uncompress(GetByteContext *gb, uint8_t **buf, int64_t *size) +int64_t ff_snappy_peek_uncompressed_length(GetByteContext *gb) +{ + int pos = bytestream2_get_bytes_left(gb); + int64_t len = decode_len(gb); + + bytestream2_seek(gb, -pos, SEEK_END); + + return len; +} + +int ff_snappy_uncompress(GetByteContext *gb, uint8_t *buf, int64_t *size) { int64_t len = decode_len(gb); int ret = 0; @@ -137,11 +147,11 @@ int ff_snappy_uncompress(GetByteContext *gb, uint8_t **buf, int64_t *size) if (len < 0) return len; - if ((ret = av_reallocp(buf, len)) < 0) - return AVERROR(ENOMEM); + if (len > *size) + return AVERROR_BUG; *size = len; - p = *buf; + p = buf; while (bytestream2_get_bytes_left(gb) > 0) { uint8_t s = bytestream2_get_byte(gb); @@ -152,13 +162,13 @@ int ff_snappy_uncompress(GetByteContext *gb, uint8_t **buf, int64_t *size) ret = snappy_literal(gb, p, len, val); break; case SNAPPY_COPY_1: - ret = snappy_copy1(gb, *buf, p, len, val); + ret = snappy_copy1(gb, buf, p, len, val); break; case SNAPPY_COPY_2: - ret = snappy_copy2(gb, *buf, p, len, val); + ret = snappy_copy2(gb, buf, p, len, val); break; case SNAPPY_COPY_4: - ret = snappy_copy4(gb, *buf, p, len, val); + ret = snappy_copy4(gb, buf, p, len, val); break; } -- cgit v1.2.3