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authorAndreas Rheinhardt <andreas.rheinhardt@gmail.com>2020-10-12 05:59:34 +0200
committerAndreas Rheinhardt <andreas.rheinhardt@gmail.com>2020-10-12 22:35:40 +0200
commit3977aeb78cb88575171bbbb515520cb01e9bbe15 (patch)
tree7badb4445dfb5384909b42ebe82ca75f474473aa /libavcodec
parent9eb7d8b45d0497d75e5655b79d9eea63bedc833c (diff)
downloadffmpeg-3977aeb78cb88575171bbbb515520cb01e9bbe15.tar.gz
avcodec/speedhq: Avoid reversing BE codes for LE bitstream reader
Reviewed-by: Paul B Mahol <onemda@gmail.com> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Diffstat (limited to 'libavcodec')
-rw-r--r--libavcodec/speedhq.c41
1 files changed, 9 insertions, 32 deletions
diff --git a/libavcodec/speedhq.c b/libavcodec/speedhq.c
index 5759cdb036..30a6924321 100644
--- a/libavcodec/speedhq.c
+++ b/libavcodec/speedhq.c
@@ -558,40 +558,17 @@ static av_cold void compute_alpha_vlcs(void)
level_symbols, 2, 2, 288);
}
-static uint32_t reverse(uint32_t num, int bits)
-{
- return bitswap_32(num) >> (32 - bits);
-}
-
-static void reverse_code(const uint16_t *code, const uint8_t *bits,
- uint16_t *reversed_code, int num_entries)
-{
- int i;
- for (i = 0; i < num_entries; i++) {
- reversed_code[i] = reverse(code[i], bits[i]);
- }
-}
-
static av_cold void speedhq_static_init(void)
{
- uint16_t ff_mpeg12_vlc_dc_lum_code_reversed[12];
- uint16_t ff_mpeg12_vlc_dc_chroma_code_reversed[12];
-
- /* Exactly the same as MPEG-2, except little-endian. */
- reverse_code(ff_mpeg12_vlc_dc_lum_code,
- ff_mpeg12_vlc_dc_lum_bits,
- ff_mpeg12_vlc_dc_lum_code_reversed,
- 12);
- INIT_LE_VLC_STATIC(&dc_lum_vlc_le, DC_VLC_BITS, 12,
- ff_mpeg12_vlc_dc_lum_bits, 1, 1,
- ff_mpeg12_vlc_dc_lum_code_reversed, 2, 2, 512);
- reverse_code(ff_mpeg12_vlc_dc_chroma_code,
- ff_mpeg12_vlc_dc_chroma_bits,
- ff_mpeg12_vlc_dc_chroma_code_reversed,
- 12);
- INIT_LE_VLC_STATIC(&dc_chroma_vlc_le, DC_VLC_BITS, 12,
- ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
- ff_mpeg12_vlc_dc_chroma_code_reversed, 2, 2, 514);
+ /* Exactly the same as MPEG-2, except for a little-endian reader. */
+ INIT_CUSTOM_VLC_STATIC(&dc_lum_vlc_le, DC_VLC_BITS, 12,
+ ff_mpeg12_vlc_dc_lum_bits, 1, 1,
+ ff_mpeg12_vlc_dc_lum_code, 2, 2,
+ INIT_VLC_OUTPUT_LE, 512);
+ INIT_CUSTOM_VLC_STATIC(&dc_chroma_vlc_le, DC_VLC_BITS, 12,
+ ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
+ ff_mpeg12_vlc_dc_chroma_code, 2, 2,
+ INIT_VLC_OUTPUT_LE, 514);
ff_rl_init(&rl_speedhq, speedhq_static_rl_table_store);
INIT_2D_VLC_RL(rl_speedhq, 674, INIT_VLC_LE);