mirror of https://github.com/FFmpeg/FFmpeg.git
Originally committed as revision 26270 to svn://svn.ffmpeg.org/ffmpeg/trunkoldabi
parent
c392cc0a64
commit
d267b339e4
9 changed files with 699 additions and 1 deletions
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/*
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* Lagarith lossless decoder |
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* Copyright (c) 2009 Nathan Caldwell <saintdev (at) gmail.com> |
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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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/**
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* @file libavcodec/lagarith.c |
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* Lagarith lossless decoder |
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* @author Nathan Caldwell |
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*/ |
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#include "avcodec.h" |
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#include "get_bits.h" |
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#include "mathops.h" |
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#include "dsputil.h" |
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#include "lagarithrac.h" |
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enum LagarithFrameType { |
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FRAME_RAW = 1, /*!< uncompressed */ |
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FRAME_U_RGB24 = 2, /*!< unaligned RGB24 */ |
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FRAME_ARITH_YUY2 = 3, /*!< arithmetic coded YUY2 */ |
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FRAME_ARITH_RGB24 = 4, /*!< arithmetic coded RGB24 */ |
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FRAME_SOLID_GRAY = 5, /*!< solid grayscale color frame */ |
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FRAME_SOLID_COLOR = 6, /*!< solid non-grayscale color frame */ |
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FRAME_OLD_ARITH_RGB = 7, /*!< obsolete arithmetic coded RGB (no longer encoded by upstream since version 1.1.0) */ |
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FRAME_ARITH_RGBA = 8, /*!< arithmetic coded RGBA */ |
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FRAME_SOLID_RGBA = 9, /*!< solid RGBA color frame */ |
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FRAME_ARITH_YV12 = 10, /*!< arithmetic coded YV12 */ |
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FRAME_REDUCED_RES = 11, /*!< reduced resolution YV12 frame */ |
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}; |
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typedef struct LagarithContext { |
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AVCodecContext *avctx; |
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AVFrame picture; |
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DSPContext dsp; |
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int zeros; /*!< number of consecutive zero bytes encountered */ |
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int zeros_rem; /*!< number of zero bytes remaining to output */ |
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} LagarithContext; |
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/**
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* Compute the 52bit mantissa of 1/(double)denom. |
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* This crazy format uses floats in an entropy coder and we have to match x86 |
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* rounding exactly, thus ordinary floats aren't portable enough. |
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* @param denom denominator |
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* @return 52bit mantissa |
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* @see softfloat_mul |
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*/ |
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static uint64_t softfloat_reciprocal(uint32_t denom) |
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{ |
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int shift = av_log2(denom - 1) + 1; |
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uint64_t ret = (1ULL << 52) / denom; |
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uint64_t err = (1ULL << 52) - ret * denom; |
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ret <<= shift; |
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err <<= shift; |
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err += denom / 2; |
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return ret + err / denom; |
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} |
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/**
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* (uint32_t)(x*f), where f has the given mantissa, and exponent 0 |
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* Used in combination with softfloat_reciprocal computes x/(double)denom. |
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* @param x 32bit integer factor |
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* @param mantissa mantissa of f with exponent 0 |
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* @return 32bit integer value (x*f) |
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* @see softfloat_reciprocal |
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*/ |
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static uint32_t softfloat_mul(uint32_t x, uint64_t mantissa) |
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{ |
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uint64_t l = x * (mantissa & 0xffffffff); |
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uint64_t h = x * (mantissa >> 32); |
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h += l >> 32; |
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l &= 0xffffffff; |
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l += 1 << av_log2(h >> 21); |
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h += l >> 32; |
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return h >> 20; |
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} |
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static uint8_t lag_calc_zero_run(int8_t x) |
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{ |
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return (x << 1) ^ (x >> 7); |
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} |
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static int lag_decode_prob(GetBitContext *gb, uint32_t *value) |
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{ |
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static const uint8_t series[] = { 1, 2, 3, 5, 8, 13, 21 }; |
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int i; |
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int bit = 0; |
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int bits = 0; |
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int prevbit = 0; |
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unsigned val; |
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for (i = 0; i < 7; i++) { |
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if (prevbit && bit) |
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break; |
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prevbit = bit; |
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bit = get_bits1(gb); |
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if (bit && !prevbit) |
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bits += series[i]; |
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} |
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bits--; |
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if (bits < 0 || bits > 31) { |
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*value = 0; |
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return -1; |
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} else if (bits == 0) { |
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*value = 0; |
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return 0; |
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} |
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val = get_bits_long(gb, bits); |
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val |= 1 << bits; |
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*value = val - 1; |
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return 0; |
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} |
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static int lag_read_prob_header(lag_rac *rac, GetBitContext *gb) |
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{ |
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int i, j, scale_factor; |
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unsigned prob, cumulative_target; |
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unsigned cumul_prob = 0; |
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unsigned scaled_cumul_prob = 0; |
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rac->prob[0] = 0; |
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rac->prob[257] = UINT_MAX; |
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/* Read probabilities from bitstream */ |
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for (i = 1; i < 257; i++) { |
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if (lag_decode_prob(gb, &rac->prob[i]) < 0) { |
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av_log(rac->avctx, AV_LOG_ERROR, "Invalid probability encountered.\n"); |
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return -1; |
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} |
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if ((uint64_t)cumul_prob + rac->prob[i] > UINT_MAX) { |
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av_log(rac->avctx, AV_LOG_ERROR, "Integer overflow encountered in cumulative probability calculation.\n"); |
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return -1; |
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} |
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cumul_prob += rac->prob[i]; |
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if (!rac->prob[i]) { |
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if (lag_decode_prob(gb, &prob)) { |
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av_log(rac->avctx, AV_LOG_ERROR, "Invalid probability run encountered.\n"); |
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return -1; |
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} |
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if (prob > 257 - i) |
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prob = 257 - i; |
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for (j = 0; j < prob; j++) |
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rac->prob[++i] = 0; |
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} |
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} |
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if (!cumul_prob) { |
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av_log(rac->avctx, AV_LOG_ERROR, "All probabilities are 0!\n"); |
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return -1; |
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} |
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/* Scale probabilities so cumulative probability is an even power of 2. */ |
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scale_factor = av_log2(cumul_prob); |
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if (cumul_prob & (cumul_prob - 1)) { |
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uint64_t mul = softfloat_reciprocal(cumul_prob); |
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for (i = 1; i < 257; i++) { |
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rac->prob[i] = softfloat_mul(rac->prob[i], mul); |
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scaled_cumul_prob += rac->prob[i]; |
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} |
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scale_factor++; |
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cumulative_target = 1 << scale_factor; |
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if (scaled_cumul_prob > cumulative_target) { |
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av_log(rac->avctx, AV_LOG_ERROR, |
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"Scaled probabilities are larger than target!\n"); |
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return -1; |
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} |
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scaled_cumul_prob = cumulative_target - scaled_cumul_prob; |
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for (i = 1; scaled_cumul_prob; i = (i & 0x7f) + 1) { |
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if (rac->prob[i]) { |
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rac->prob[i]++; |
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scaled_cumul_prob--; |
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} |
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/* Comment from reference source:
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* if (b & 0x80 == 0) { // order of operations is 'wrong'; it has been left this way
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* // since the compression change is negligable and fixing it
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* // breaks backwards compatibilty
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* b =- (signed int)b; |
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* b &= 0xFF; |
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* } else { |
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* b++; |
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* b &= 0x7f; |
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* } |
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*/ |
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} |
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} |
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rac->scale = scale_factor; |
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/* Fill probability array with cumulative probability for each symbol. */ |
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for (i = 1; i < 257; i++) |
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rac->prob[i] += rac->prob[i - 1]; |
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return 0; |
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} |
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static void add_lag_median_prediction(uint8_t *dst, uint8_t *src1, |
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uint8_t *diff, int w, int *left, |
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int *left_top) |
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{ |
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/* This is almost identical to add_hfyu_median_prediction in dsputil.h.
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* However the &0xFF on the gradient predictor yealds incorrect output |
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* for lagarith. |
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*/ |
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int i; |
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uint8_t l, lt; |
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l = *left; |
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lt = *left_top; |
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for (i = 0; i < w; i++) { |
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l = mid_pred(l, src1[i], l + src1[i] - lt) + diff[i]; |
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lt = src1[i]; |
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dst[i] = l; |
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} |
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*left = l; |
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*left_top = lt; |
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} |
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static void lag_pred_line(LagarithContext *l, uint8_t *buf, |
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int width, int stride, int line) |
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{ |
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int L, TL; |
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if (!line) { |
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/* Left prediction only for first line */ |
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L = l->dsp.add_hfyu_left_prediction(buf + 1, buf + 1, |
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width - 1, buf[0]); |
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return; |
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} else if (line == 1) { |
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/* Second line, left predict first pixel, the rest of the line is median predicted */ |
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/* FIXME: In the case of RGB this pixel is top predicted */ |
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TL = buf[-stride]; |
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} else { |
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/* Top left is 2 rows back, last pixel */ |
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TL = buf[width - (2 * stride) - 1]; |
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} |
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/* Left pixel is actually prev_row[width] */ |
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L = buf[width - stride - 1]; |
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add_lag_median_prediction(buf, buf - stride, buf, |
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width, &L, &TL); |
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} |
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static int lag_decode_line(LagarithContext *l, lag_rac *rac, |
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uint8_t *dst, int width, int stride, |
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int esc_count) |
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{ |
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int i = 0; |
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int ret = 0; |
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if (!esc_count) |
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esc_count = -1; |
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/* Output any zeros remaining from the previous run */ |
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handle_zeros: |
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if (l->zeros_rem) { |
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int count = FFMIN(l->zeros_rem, width - i); |
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memset(dst + i, 0, count); |
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i += count; |
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l->zeros_rem -= count; |
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} |
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while (i < width) { |
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dst[i] = lag_get_rac(rac); |
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ret++; |
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if (dst[i]) |
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l->zeros = 0; |
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else |
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l->zeros++; |
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i++; |
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if (l->zeros == esc_count) { |
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int index = lag_get_rac(rac); |
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ret++; |
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l->zeros = 0; |
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l->zeros_rem = lag_calc_zero_run(index); |
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goto handle_zeros; |
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} |
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} |
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return ret; |
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} |
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static int lag_decode_zero_run_line(LagarithContext *l, uint8_t *dst, |
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const uint8_t *src, int width, |
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int esc_count) |
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{ |
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int i = 0; |
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int count; |
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uint8_t zero_run = 0; |
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const uint8_t *start = src; |
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uint8_t mask1 = -(esc_count < 2); |
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uint8_t mask2 = -(esc_count < 3); |
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uint8_t *end = dst + (width - 2); |
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output_zeros: |
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if (l->zeros_rem) { |
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count = FFMIN(l->zeros_rem, width - i); |
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memset(dst, 0, count); |
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l->zeros_rem -= count; |
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dst += count; |
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} |
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while (dst < end) { |
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i = 0; |
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while (!zero_run && dst + i < end) { |
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i++; |
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zero_run = |
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!(src[i] | (src[i + 1] & mask1) | (src[i + 2] & mask2)); |
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} |
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if (zero_run) { |
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zero_run = 0; |
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i += esc_count; |
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memcpy(dst, src, i); |
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dst += i; |
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l->zeros_rem = lag_calc_zero_run(src[i]); |
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src += i + 1; |
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goto output_zeros; |
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} else { |
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memcpy(dst, src, i); |
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src += i; |
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} |
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} |
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return start - src; |
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} |
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static int lag_decode_arith_plane(LagarithContext *l, uint8_t *dst, |
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int width, int height, int stride, |
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const uint8_t *src, int src_size) |
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{ |
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int i = 0; |
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int read = 0; |
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uint32_t length; |
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uint32_t offset = 1; |
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int esc_count = src[0]; |
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GetBitContext gb; |
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lag_rac rac; |
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rac.avctx = l->avctx; |
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l->zeros = 0; |
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if (esc_count < 4) { |
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length = width * height; |
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if (esc_count && AV_RL32(src + 1) < length) { |
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length = AV_RL32(src + 1); |
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offset += 4; |
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} |
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init_get_bits(&gb, src + offset, src_size * 8); |
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if (lag_read_prob_header(&rac, &gb) < 0) |
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return -1; |
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lag_rac_init(&rac, &gb, length - stride); |
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for (i = 0; i < height; i++) |
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read += lag_decode_line(l, &rac, dst + (i * stride), width, |
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stride, esc_count); |
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if (read > length) |
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av_log(l->avctx, AV_LOG_WARNING, |
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"Output more bytes than length (%d of %d)\n", read, |
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length); |
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} else if (esc_count < 8) { |
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esc_count -= 4; |
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if (esc_count > 0) { |
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/* Zero run coding only, no range coding. */ |
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for (i = 0; i < height; i++) |
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src += lag_decode_zero_run_line(l, dst + (i * stride), src, |
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width, esc_count); |
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} else { |
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/* Plane is stored uncompressed */ |
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for (i = 0; i < height; i++) { |
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memcpy(dst + (i * stride), src, width); |
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src += width; |
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} |
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} |
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} else if (esc_count == 0xff) { |
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/* Plane is a solid run of 0 bytes */ |
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for (i = 0; i < height; i++) |
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memset(dst + i * stride, 0, width); |
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} else { |
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av_log(l->avctx, AV_LOG_ERROR, |
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"Invalid zero run escape code! (%#x)\n", esc_count); |
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return -1; |
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} |
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for (i = 0; i < height; i++) { |
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lag_pred_line(l, dst, width, stride, i); |
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dst += stride; |
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} |
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return 0; |
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} |
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/**
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* Decode a frame. |
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* @param avctx codec context |
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* @param data output AVFrame |
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* @param data_size size of output data or 0 if no picture is returned |
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* @param avpkt input packet |
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* @return number of consumed bytes on success or negative if decode fails |
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*/ |
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static int lag_decode_frame(AVCodecContext *avctx, |
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void *data, int *data_size, AVPacket *avpkt) |
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{ |
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const uint8_t *buf = avpkt->data; |
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int buf_size = avpkt->size; |
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LagarithContext *l = avctx->priv_data; |
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AVFrame *const p = &l->picture; |
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uint8_t frametype = 0; |
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uint32_t offset_gu = 0, offset_bv = 0, offset_ry = 9; |
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AVFrame *picture = data; |
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if (p->data[0]) |
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avctx->release_buffer(avctx, p); |
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p->reference = 0; |
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p->key_frame = 1; |
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frametype = buf[0]; |
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offset_gu = AV_RL32(buf + 1); |
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offset_bv = AV_RL32(buf + 5); |
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switch (frametype) { |
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case FRAME_ARITH_YV12: |
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avctx->pix_fmt = PIX_FMT_YUV420P; |
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if (avctx->get_buffer(avctx, p) < 0) { |
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); |
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return -1; |
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} |
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lag_decode_arith_plane(l, p->data[0], avctx->width, avctx->height, |
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p->linesize[0], buf + offset_ry, |
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buf_size); |
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lag_decode_arith_plane(l, p->data[2], avctx->width / 2, |
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avctx->height / 2, p->linesize[2], |
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buf + offset_gu, buf_size); |
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lag_decode_arith_plane(l, p->data[1], avctx->width / 2, |
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avctx->height / 2, p->linesize[1], |
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buf + offset_bv, buf_size); |
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break; |
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default: |
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av_log(avctx, AV_LOG_ERROR, |
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"Unsupported Lagarith frame type: %#x\n", frametype); |
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return -1; |
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} |
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*picture = *p; |
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*data_size = sizeof(AVFrame); |
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return buf_size; |
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} |
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static av_cold int lag_decode_init(AVCodecContext *avctx) |
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{ |
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LagarithContext *l = avctx->priv_data; |
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l->avctx = avctx; |
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dsputil_init(&l->dsp, avctx); |
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return 0; |
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} |
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static av_cold int lag_decode_end(AVCodecContext *avctx) |
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{ |
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LagarithContext *l = avctx->priv_data; |
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if (l->picture.data[0]) |
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avctx->release_buffer(avctx, &l->picture); |
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return 0; |
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} |
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AVCodec lagarith_decoder = { |
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"lagarith", |
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CODEC_TYPE_VIDEO, |
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CODEC_ID_LAGARITH, |
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sizeof(LagarithContext), |
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lag_decode_init, |
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NULL, |
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lag_decode_end, |
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lag_decode_frame, |
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CODEC_CAP_DR1, |
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.long_name = NULL_IF_CONFIG_SMALL("Lagarith lossless"), |
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}; |
@ -0,0 +1,58 @@ |
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/*
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* Lagarith range decoder |
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* Copyright (c) 2009 Nathan Caldwell <saintdev (at) gmail.com> |
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* Copyright (c) 2009 David Conrad |
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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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/**
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* @file libavcodec/lagarithrac.c |
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* Lagarith range decoder |
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* @author Nathan Caldwell |
||||
* @author David Conrad |
||||
*/ |
||||
|
||||
#include "get_bits.h" |
||||
#include "lagarithrac.h" |
||||
|
||||
void lag_rac_init(lag_rac *l, GetBitContext *gb, int length) |
||||
{ |
||||
int i, j; |
||||
|
||||
/* According to reference decoder "1st byte is garbage",
|
||||
* however, it gets skipped by the call to align_get_bits() |
||||
*/ |
||||
align_get_bits(gb); |
||||
l->bytestream_start = |
||||
l->bytestream = gb->buffer + get_bits_count(gb) / 8; |
||||
l->bytestream_end = l->bytestream_start + length; |
||||
|
||||
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; |
||||
} |
@ -0,0 +1,116 @@ |
||||
/*
|
||||
* 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 libavcodec/lagarithrac.h |
||||
* Lagarith range decoder |
||||
* @author Nathan Caldwell |
||||
* @author David Conrad |
||||
*/ |
||||
|
||||
#ifndef AVCODEC_LAGARITHRAC_H |
||||
#define AVCODEC_LAGARITHRAC_H |
||||
|
||||
#include <stdint.h> |
||||
#include "libavutil/common.h" |
||||
#include "libavutil/intreadwrite.h" |
||||
#include "avcodec.h" |
||||
#include "get_bits.h" |
||||
|
||||
typedef struct lag_rac { |
||||
AVCodecContext *avctx; |
||||
unsigned low; |
||||
unsigned range; |
||||
unsigned scale; /*!< Number of bits of precision in range. */ |
||||
unsigned hash_shift; /*!< Number of bits to shift to calculate hash for radix search. */ |
||||
|
||||
const uint8_t *bytestream_start; /*!< Start of input bytestream. */ |
||||
const uint8_t *bytestream; /*!< Current position in input bytestream. */ |
||||
const uint8_t *bytestream_end; /*!< End position of input bytestream. */ |
||||
|
||||
uint32_t prob[258]; /*!< Table of cumulative probability for each symbol. */ |
||||
uint8_t range_hash[256]; /*!< Hash table mapping upper byte to approximate symbol. */ |
||||
} lag_rac; |
||||
|
||||
void lag_rac_init(lag_rac *l, GetBitContext *gb, int length); |
||||
|
||||
/* TODO: Optimize */ |
||||
static inline void lag_rac_refill(lag_rac *l) |
||||
{ |
||||
while (l->range <= 0x800000) { |
||||
l->low <<= 8; |
||||
l->range <<= 8; |
||||
l->low |= 0xff & (AV_RB16(l->bytestream) >> 1); |
||||
if (l->bytestream < l->bytestream_end) |
||||
l->bytestream++; |
||||
} |
||||
} |
||||
|
||||
/**
|
||||
* Decode a single byte from the compressed plane described by *l. |
||||
* @param l pointer to lag_rac for the current plane |
||||
* @return next byte of decoded data |
||||
*/ |
||||
static inline uint8_t lag_get_rac(lag_rac *l) |
||||
{ |
||||
unsigned range_scaled, low_scaled, div; |
||||
int val; |
||||
uint8_t shift; |
||||
|
||||
lag_rac_refill(l); |
||||
|
||||
range_scaled = l->range >> l->scale; |
||||
|
||||
if (l->low < range_scaled * l->prob[255]) { |
||||
/* val = 0 is frequent enough to deserve a shortcut */ |
||||
if (l->low < range_scaled * l->prob[1]) { |
||||
val = 0; |
||||
} else { |
||||
/* FIXME __builtin_clz is ~20% faster here, but not allowed in generic code. */ |
||||
shift = 30 - av_log2(range_scaled); |
||||
div = ((range_scaled << shift) + (1 << 23) - 1) >> 23; |
||||
/* low>>24 ensures that any cases too big for exact FASTDIV are
|
||||
* under- rather than over-estimated |
||||
*/ |
||||
low_scaled = FASTDIV(l->low - (l->low >> 24), div); |
||||
shift -= l->hash_shift; |
||||
shift &= 31; |
||||
low_scaled = (low_scaled << shift) | (low_scaled >> (32 - shift)); |
||||
/* low_scaled is now a lower bound of low/range_scaled */ |
||||
val = l->range_hash[(uint8_t) low_scaled]; |
||||
while (l->low >= range_scaled * l->prob[val + 1]) |
||||
val++; |
||||
} |
||||
|
||||
l->range = range_scaled * (l->prob[val + 1] - l->prob[val]); |
||||
} else { |
||||
val = 255; |
||||
l->range -= range_scaled * l->prob[255]; |
||||
} |
||||
|
||||
l->low -= range_scaled * l->prob[val]; |
||||
|
||||
return val; |
||||
} |
||||
|
||||
|
||||
#endif /* AVCODEC_LAGARITHRAC_H */ |
Loading…
Reference in new issue