diff options
author | Tom Butterworth <bangnoise@gmail.com> | 2015-07-16 15:23:22 +0300 |
---|---|---|
committer | Michael Niedermayer <michael@niedermayer.cc> | 2015-07-16 21:41:07 +0300 |
commit | 17ee24af7e5f7112fe25c734236d521f9e35d80d (patch) | |
tree | 272bb8fb9c8f1792fccf287a138e09e064425e71 | |
parent | c4dfb76fa7e4d51fd4ca686a63499245c0687a84 (diff) |
avcodec/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.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
-rw-r--r-- | libavcodec/hapdec.c | 7 | ||||
-rw-r--r-- | libavcodec/snappy.c | 24 | ||||
-rw-r--r-- | libavcodec/snappy.h | 19 |
3 files changed, 37 insertions, 13 deletions
diff --git a/libavcodec/hapdec.c b/libavcodec/hapdec.c index 5986a3f208..7eff9e0273 100644 --- a/libavcodec/hapdec.c +++ b/libavcodec/hapdec.c @@ -107,8 +107,13 @@ static int setup_texture(AVCodecContext *avctx, size_t length) compressorstr = "none"; break; case HAP_COMP_SNAPPY: + snappy_size = ff_snappy_peek_uncompressed_length(gbc); + ret = av_reallocp(&ctx->snappied, snappy_size); + if (ret < 0) { + return ret; + } /* Uncompress the frame */ - ret = ff_snappy_uncompress(gbc, &ctx->snappied, &snappy_size); + ret = ff_snappy_uncompress(gbc, ctx->snappied, &snappy_size); if (ret < 0) { av_log(avctx, AV_LOG_ERROR, "Snappy uncompress error\n"); return ret; diff --git a/libavcodec/snappy.c b/libavcodec/snappy.c index 553d713281..7900b0f978 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_BUFFER_TOO_SMALL; *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; } diff --git a/libavcodec/snappy.h b/libavcodec/snappy.h index b283183cb6..a65cb3aa1b 100644 --- a/libavcodec/snappy.h +++ b/libavcodec/snappy.h @@ -38,14 +38,23 @@ #include "bytestream.h" /** - * Decompress an input buffer using Snappy algorithm. Caller is - * responsible of freeing the memory allocated in buf. + * Get the uncompressed length of an input buffer compressed using the Snappy + * algorithm. The GetByteContext is not advanced. * * @param gb input GetByteContext. - * @param buf output buffer pointer. - * @param size output buffer size. + * @return A positive length on success, AVERROR otherwise. + */ + int64_t ff_snappy_peek_uncompressed_length(GetByteContext *gb); + +/** + * Decompress an input buffer using Snappy algorithm. + * + * @param gb input GetByteContext. + * @param buf input buffer pointer. + * @param size input/output on input, the size of buffer, on output, the size + * of the uncompressed data. * @return 0 if success, AVERROR otherwise. */ -int ff_snappy_uncompress(GetByteContext *gb, uint8_t **buf, int64_t *size); +int ff_snappy_uncompress(GetByteContext *gb, uint8_t *buf, int64_t *size); #endif /* AVCODEC_SNAPPY_H */ |