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e7a629049f
Forgotten in70a7df049c. Using the wrong scantable matters for codecs for which both scantables can differ, namely the MPEG-4 decoder and the WMV1/2 codecs. For WMV1 it can lead to wrong output in case the IDCT permutation is FF_IDCT_PERM_PARTTRANS, because in this case the entries of of the intra scantable's raster end are not always <= the corresponding entries of the inter scantable's raster end when the former is initialized via ff_wmv1_scantable[1] and the latter via ff_wmv1_scantable[0]. FF_IDCT_PERM_PARTTRANS is used iff the Neon IDCT is used (for both arm and aarch64).* Said IDCT is not used during FATE, so that this issue went unnoticed. WMV2 uses the same scantables, but uses a custom IDCT which always uses FF_IDCT_PERM_NONE for which the inter_scantable, so that the output is always correct for it. The scantable for MPEG-4 can change mid-stream (for the decoder), but sincec41818dc5donly the intra scantable is updated, so that both scantables can get out of sync. In such a case the unquantize intra functions could unquantize an incorrect number of coefficients. Using raster_end of the wrong scantable can also lead to an unnecessarily large amount of coefficients unquantized. *: FF_IDCT_PERM_SIMPLE and FF_IDCT_PERM_TRANSPOSE would also not work, but they are not used at all by arm and aarch64. Reviewed-by: Martin Storsjö <martin@martin.st> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
103 lines
3.1 KiB
C
103 lines
3.1 KiB
C
/*
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* Optimization of some functions from mpegvideo.c for armv5te
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* Copyright (c) 2007 Siarhei Siamashka <ssvb@users.sourceforge.net>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "libavutil/attributes.h"
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#include "libavutil/avassert.h"
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#include "libavcodec/avcodec.h"
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#include "libavcodec/mpegvideo.h"
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#include "mpegvideo_arm.h"
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void ff_dct_unquantize_h263_armv5te(int16_t *block, int qmul, int qadd, int count);
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#ifdef ENABLE_ARM_TESTS
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/**
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* H.263 dequantizer supplementary function, it is performance critical and needs to
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* have optimized implementations for each architecture. Is also used as a reference
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* implementation in regression tests
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*/
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static inline void dct_unquantize_h263_helper_c(int16_t *block, int qmul, int qadd, int count)
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{
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int i, level;
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for (i = 0; i < count; i++) {
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level = block[i];
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if (level) {
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if (level < 0) {
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level = level * qmul - qadd;
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} else {
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level = level * qmul + qadd;
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}
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block[i] = level;
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}
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}
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}
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#endif
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static void dct_unquantize_h263_intra_armv5te(const MPVContext *s,
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int16_t *block, int n, int qscale)
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{
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int level, qmul, qadd;
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int nCoeffs;
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av_assert2(s->block_last_index[n]>=0);
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qmul = qscale << 1;
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if (!s->h263_aic) {
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if (n < 4)
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level = block[0] * s->y_dc_scale;
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else
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level = block[0] * s->c_dc_scale;
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qadd = (qscale - 1) | 1;
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}else{
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qadd = 0;
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level = block[0];
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}
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if(s->ac_pred)
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nCoeffs=63;
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else
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nCoeffs = s->intra_scantable.raster_end[s->block_last_index[n]];
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ff_dct_unquantize_h263_armv5te(block, qmul, qadd, nCoeffs + 1);
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block[0] = level;
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}
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static void dct_unquantize_h263_inter_armv5te(const MPVContext *s,
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int16_t *block, int n, int qscale)
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{
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int qmul, qadd;
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int nCoeffs;
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av_assert2(s->block_last_index[n]>=0);
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qadd = (qscale - 1) | 1;
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qmul = qscale << 1;
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nCoeffs= s->inter_scantable.raster_end[ s->block_last_index[n] ];
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ff_dct_unquantize_h263_armv5te(block, qmul, qadd, nCoeffs + 1);
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}
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av_cold void ff_mpv_unquantize_init_armv5te(MPVUnquantDSPContext *s)
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{
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s->dct_unquantize_h263_intra = dct_unquantize_h263_intra_armv5te;
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s->dct_unquantize_h263_inter = dct_unquantize_h263_inter_armv5te;
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}
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