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author | Reimar Döffinger <Reimar.Doeffinger@gmx.de> | 2007-01-28 16:49:51 +0000 |
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committer | Reimar Döffinger <Reimar.Doeffinger@gmx.de> | 2007-01-28 16:49:51 +0000 |
commit | a737f1dfdb588079bdd1c97a77744993dafa8c62 (patch) | |
tree | 1d51967ad977d9f24ef3a0df21a0935c00da8d4b | |
parent | 910c62e1fcdababaffacf9f2f015cbd3930a2dfe (diff) | |
download | ffmpeg-streaming-a737f1dfdb588079bdd1c97a77744993dafa8c62.zip ffmpeg-streaming-a737f1dfdb588079bdd1c97a77744993dafa8c62.tar.gz |
LZO optimization: check input buffer bounds less frequently if padded
Originally committed as revision 7747 to svn://svn.ffmpeg.org/ffmpeg/trunk
-rw-r--r-- | libavcodec/lzo.c | 34 | ||||
-rw-r--r-- | libavcodec/lzo.h | 2 |
2 files changed, 23 insertions, 13 deletions
diff --git a/libavcodec/lzo.c b/libavcodec/lzo.c index eed3b8c..0ee7eca 100644 --- a/libavcodec/lzo.c +++ b/libavcodec/lzo.c @@ -26,7 +26,7 @@ //! define if we may write up to 12 bytes beyond the output buffer #define OUTBUF_PADDED 1 -//! define if we may read up to 4 bytes beyond the input buffer +//! define if we may read up to 8 bytes beyond the input buffer #define INBUF_PADDED 1 typedef struct LZOContext { uint8_t *in, *in_end; @@ -45,6 +45,12 @@ static inline int get_byte(LZOContext *c) { return 1; } +#ifdef INBUF_PADDED +#define GETB(c) (*(c).in++) +#else +#define GETB(c) get_byte(&(c)) +#endif + /** * \brief decode a length value in the coding used by lzo * \param x previous byte value @@ -170,10 +176,10 @@ int lzo1x_decode(void *out, int *outlen, void *in, int *inlen) { c.out = c.out_start = out; c.out_end = (uint8_t *)out + * outlen; c.error = 0; - x = get_byte(&c); + x = GETB(c); if (x > 17) { copy(&c, x - 17); - x = get_byte(&c); + x = GETB(c); if (x < 16) c.error |= LZO_ERROR; } while (!c.error) { @@ -181,16 +187,16 @@ int lzo1x_decode(void *out, int *outlen, void *in, int *inlen) { if (x >> 4) { if (x >> 6) { cnt = (x >> 5) - 1; - back = (get_byte(&c) << 3) + ((x >> 2) & 7) + 1; + back = (GETB(c) << 3) + ((x >> 2) & 7) + 1; } else if (x >> 5) { cnt = get_len(&c, x, 31); - x = get_byte(&c); - back = (get_byte(&c) << 6) + (x >> 2) + 1; + x = GETB(c); + back = (GETB(c) << 6) + (x >> 2) + 1; } else { cnt = get_len(&c, x, 7); back = (1 << 14) + ((x & 8) << 11); - x = get_byte(&c); - back += (get_byte(&c) << 6) + (x >> 2); + x = GETB(c); + back += (GETB(c) << 6) + (x >> 2); if (back == (1 << 14)) { if (cnt != 1) c.error |= LZO_ERROR; @@ -202,15 +208,15 @@ int lzo1x_decode(void *out, int *outlen, void *in, int *inlen) { case COPY: cnt = get_len(&c, x, 15); copy(&c, cnt + 3); - x = get_byte(&c); + x = GETB(c); if (x >> 4) continue; cnt = 1; - back = (1 << 11) + (get_byte(&c) << 2) + (x >> 2) + 1; + back = (1 << 11) + (GETB(c) << 2) + (x >> 2) + 1; break; case BACKPTR: cnt = 0; - back = (get_byte(&c) << 2) + (x >> 2) + 1; + back = (GETB(c) << 2) + (x >> 2) + 1; break; } copy_backptr(&c, back, cnt + 2); @@ -218,9 +224,13 @@ int lzo1x_decode(void *out, int *outlen, void *in, int *inlen) { state = cnt ? BACKPTR : COPY; if (cnt) copy(&c, cnt); - x = get_byte(&c); + x = GETB(c); + if (c.in > c.in_end) + c.error |= LZO_INPUT_DEPLETED; } *inlen = c.in_end - c.in; + if (c.in > c.in_end) + *inlen = 0; *outlen = c.out_end - c.out; return c.error; } diff --git a/libavcodec/lzo.h b/libavcodec/lzo.h index 7dc95d7..5b3d98f 100644 --- a/libavcodec/lzo.h +++ b/libavcodec/lzo.h @@ -27,7 +27,7 @@ #define LZO_INVALID_BACKPTR 4 #define LZO_ERROR 8 -#define LZO_INPUT_PADDING 4 +#define LZO_INPUT_PADDING 8 #define LZO_OUTPUT_PADDING 12 int lzo1x_decode(void *out, int *outlen, void *in, int *inlen); |