mirror of
https://github.com/xenia-project/FFmpeg.git
synced 2024-12-01 07:20:58 +00:00
d40ff29cac
* qatar/master:
asf: only set index_read if the index contained entries.
cabac: add overread protection to BRANCHLESS_GET_CABAC().
cabac: increment jump locations by one in callers of BRANCHLESS_GET_CABAC().
cabac: remove unused argument from BRANCHLESS_GET_CABAC_UPDATE().
cabac: use struct+offset instead of memory operand in BRANCHLESS_GET_CABAC().
h264: add overread protection to get_cabac_bypass_sign_x86().
h264: reindent get_cabac_bypass_sign_x86().
h264: use struct offsets in get_cabac_bypass_sign_x86().
h264: fix overreads in cabac reader.
wmall: fix seeking.
lagarith: fix buffer overreads.
dvdec: drop unnecessary dv_tablegen.h #include
build: fix doc generation errors in parallel builds
Replace memset(0) by zero initializations.
faandct: Remove FAAN_POSTSCALE define and related code.
dvenc: print allowed profiles if the video doesn't conform to any of them.
avcodec_encode_{audio,video}: only reallocate output packet when it has non-zero size.
FATE: add a test for vp8 with changing frame size.
fate: add kgv1 fate test.
oggdec: calculate correct timestamps in Ogg/FLAC
Conflicts:
libavcodec/4xm.c
libavcodec/cook.c
libavcodec/dvdata.c
libavcodec/dvdsubdec.c
libavcodec/lagarith.c
libavcodec/lagarithrac.c
libavcodec/utils.c
tests/fate/video.mak
Merged-by: Michael Niedermayer <michaelni@gmx.at>
60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
/*
|
|
* Lagarith range decoder
|
|
* Copyright (c) 2009 Nathan Caldwell <saintdev (at) gmail.com>
|
|
* Copyright (c) 2009 David Conrad
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* Lagarith range decoder
|
|
* @author Nathan Caldwell
|
|
* @author David Conrad
|
|
*/
|
|
|
|
#include "get_bits.h"
|
|
#include "lagarithrac.h"
|
|
|
|
void ff_lag_rac_init(lag_rac *l, GetBitContext *gb, int length)
|
|
{
|
|
int i, j, left;
|
|
|
|
/* According to reference decoder "1st byte is garbage",
|
|
* however, it gets skipped by the call to align_get_bits()
|
|
*/
|
|
align_get_bits(gb);
|
|
left = get_bits_left(gb) >> 3;
|
|
l->bytestream_start =
|
|
l->bytestream = gb->buffer + get_bits_count(gb) / 8;
|
|
l->bytestream_end = l->bytestream_start + left;
|
|
|
|
l->range = 0x80;
|
|
l->low = *l->bytestream >> 1;
|
|
l->hash_shift = FFMAX(l->scale - 8, 0);
|
|
|
|
for (i = j = 0; i < 256; i++) {
|
|
unsigned r = i << l->hash_shift;
|
|
while (l->prob[j + 1] <= r)
|
|
j++;
|
|
l->range_hash[i] = j;
|
|
}
|
|
|
|
/* Add conversion factor to hash_shift so we don't have to in lag_get_rac. */
|
|
l->hash_shift += 23;
|
|
}
|