On Sun, Jul 17, 2016 at 12:06:03AM +0530, Umair Khan wrote: > Hi, > > Patch attached. > > - Umair
> libavcodec/Makefile | 2 > libavcodec/alsdec.c | 284 > +++++++++++++++++++++++++++++++++++++++++- > libavcodec/mlz.c | 171 +++++++++++++++++++++++++ > libavcodec/mlz.h | 69 ++++++++++ > libavutil/softfloat_ieee754.h | 115 +++++++++++++++++ > 5 files changed, 638 insertions(+), 3 deletions(-) > 0282267108d74681f1bff6b5e6a85c603ac7052e > 0001-avcodec-alsdec-implement-floating-point-decoding.patch > From 70e65b26cc3f84c9c664c30808b43a5e1cf16eaa Mon Sep 17 00:00:00 2001 > From: Umair Khan <omerj...@gmail.com> > Date: Sat, 16 Jul 2016 23:52:39 +0530 > Subject: [PATCH 1/1] avcodec/alsdec: implement floating point decoding > > It conforms to RM22 version of the reference codec. > > Signed-off-by: Umair Khan <omerj...@gmail.com> > --- > libavcodec/Makefile | 2 +- > libavcodec/alsdec.c | 284 > +++++++++++++++++++++++++++++++++++++++++- > libavcodec/mlz.c | 171 +++++++++++++++++++++++++ > libavcodec/mlz.h | 69 ++++++++++ > libavutil/softfloat_ieee754.h | 115 +++++++++++++++++ missing update to Changelog [...] > @@ -1356,6 +1366,237 @@ static int revert_channel_correlation(ALSDecContext > *ctx, ALSBlockData *bd, > } > > > +/** multiply two softfloats and handle the rounding off > + */ > +static SoftFloat_IEEE754 multiply(SoftFloat_IEEE754 a, SoftFloat_IEEE754 b) { > + uint64_t mantissa_temp; > + uint64_t mask_64; > + int bit_count; > + int cutoff_bit_count; > + unsigned char last_2_bits; > + unsigned int mantissa; > + uint32_t return_val = 0; > + int32_t sign; > + > + sign = a.sign ^ b.sign; > + > + // Multiply mantissa bits in a 64-bit register > + mantissa_temp = (uint64_t)a.mant * (uint64_t)b.mant; > + > + // Count the valid bit count > + for (bit_count=48, mask_64=(uint64_t)0x1 << 47; !(mantissa_temp & > mask_64) && mask_64; bit_count--, mask_64>>=1); this needs some newlines for readability > + > + // Round off > + cutoff_bit_count = bit_count - 24; > + if (cutoff_bit_count > 0) { > + last_2_bits = (unsigned char)(((unsigned int)mantissa_temp >> > (cutoff_bit_count - 1)) & 0x3 ); > + if ((last_2_bits == 0x3) || ((last_2_bits == 0x1) && ((unsigned > int)mantissa_temp & ((0x1UL << (cutoff_bit_count - 1)) - 1)))) { > + // Need to round up > + mantissa_temp += (uint64_t)0x1 << cutoff_bit_count; > + } > + } > + > + mantissa = (unsigned int)(mantissa_temp >> cutoff_bit_count); > + > + // Need one more shift? > + if (mantissa & 0x01000000ul) { > + bit_count++; > + mantissa >>= 1; > + } > + > + if (!sign) { > + return_val = 0x80000000U; > + } > + > + return_val |= (a.exp + b.exp + bit_count - 47) << 23; > + return_val |= mantissa; > + return av_bits2sf_ieee754(return_val); > +} > + > + > +/** Read and decode the floating point sample data > + */ > +static int read_diff_float_data(ALSDecContext *ctx, unsigned int ra_frame) { > + AVCodecContext *avctx = ctx->avctx; > + GetBitContext *gb = &ctx->gb; > + SoftFloat_IEEE754 *acf = ctx->acf; > + int *shift_value = ctx->shift_value; > + int *last_shift_value = ctx->last_shift_value; > + int *last_acf_mantissa = ctx->last_acf_mantissa; > + int **raw_mantissa = ctx->raw_mantissa; > + int *nbits = ctx->nbits; > + unsigned char *larray = ctx->larray; > + int frame_length = ctx->cur_frame_length; > + SoftFloat_IEEE754 scale = av_int2sf_ieee754(0x1u, 23); > + unsigned int partA_flag; > + unsigned int highest_byte; > + unsigned int shift_amp; > + uint32_t tmp_32; > + int use_acf; > + int nchars; > + int i; > + int c; > + long k; > + long nbits_aligned; > + unsigned long acc; > + unsigned long j; > + uint32_t sign; > + uint32_t e; > + uint32_t mantissa; > + > + skip_bits_long(gb, 32); //num_bytes_diff_float > + use_acf = get_bits1(gb); > + > + if (ra_frame) { > + for (c = 0; c < avctx->channels; ++c) { > + last_acf_mantissa[c] = 0; > + last_shift_value[c] = 0; > + } memset() > + ff_mlz_flush_dict(ctx->mlz); > + } > + > + for (c = 0; c < avctx->channels; ++c) { > + if (use_acf) { > + //acf_flag > + if (get_bits1(gb)) { > + tmp_32 = get_bits(gb, 23); > + last_acf_mantissa[c] = tmp_32; > + } else { > + tmp_32 = last_acf_mantissa[c]; > + } > + acf[c] = av_bits2sf_ieee754(tmp_32); > + } else { > + acf[c] = FLOAT_1; > + } > + > + highest_byte = get_bits(gb, 2); > + partA_flag = get_bits1(gb); > + shift_amp = get_bits1(gb); > + > + if (shift_amp) { > + shift_value[c] = get_bits(gb, 8); > + last_shift_value[c] = shift_value[c]; > + } else { > + shift_value[c] = last_shift_value[c]; > + } > + > + if (partA_flag) { > + if (!get_bits1(gb)) { //uncompressed > + for (i = 0; i < frame_length; ++i) { > + if (ctx->raw_samples[c][i] == 0) { > + ctx->raw_mantissa[c][i] = get_bits_long(gb, 32); > + } > + } > + } else { //compressed > + nchars = 0; > + for (i = 0; i < frame_length; ++i) { > + if (ctx->raw_samples[c][i] == 0) { > + nchars += 4; > + } > + } > + > + tmp_32 = ff_mlz_decompression(ctx->mlz, gb, nchars, larray); > + if(tmp_32 != nchars) { > + av_log(ctx->avctx, AV_LOG_ERROR, "Error in MLZ > decompression (%d, %d).\n", tmp_32, nchars); > + return AVERROR_INVALIDDATA; > + } > + > + for (i = 0; i < frame_length; ++i) { > + tmp_32 = (larray[i] << 24) | larray[i+1] << 16 | > larray[i+2] << 8 | larray[i+3]; AV_RB32() > + ctx->raw_mantissa[c][i] = tmp_32; > + } > + } > + } > + > + //decode part B > + if (highest_byte) { > + for (i = 0; i < frame_length; ++i) { > + if (ctx->raw_samples[c][i] != 0) { > + //The following logic is taken from Tabel 14.45 and > 14.46 from the ISO spec > + if (av_cmp_sf_ieee754(acf[c], FLOAT_1)) { > + nbits[i] = 23 - av_log2(abs(ctx->raw_samples[c][i])); > + } else { > + nbits[i] = 23; > + } > + nbits[i] = FFMIN(nbits[i], highest_byte*8); > + } > + } > + > + if (!get_bits1(gb)) { //uncompressed > + for (i = 0; i < frame_length; ++i) { > + if (ctx->raw_samples[c][i] != 0) { > + raw_mantissa[c][i] = get_bits(gb, nbits[i]); > + } > + } > + } else { //compressed > + nchars = 0; > + for (i = 0; i < frame_length; ++i) { > + if (ctx->raw_samples[c][i]) { > + nchars += (int) nbits[i] / 8; > + if (nbits[i] % 8 > 0) { can nbits[] be < 0 ? if not then &7 is better than %8 [...] > +static int decode_string(MLZDict *dict, unsigned char *buff, int > string_code, int *first_char_code, unsigned long bufsize) { > + unsigned long count, offset; > + int current_code, parent_code, tmp_code; > + > + count = 0; > + current_code = string_code; > + *first_char_code = CODE_UNSET; > + > + while (count < bufsize) { > + switch (current_code) { > + case CODE_UNSET: > + return count; > + break; > + default: > + if (current_code < FIRST_CODE) { > + *first_char_code = current_code; > + buff[0] = current_code; > + count++; > + return count; > + } else { > + offset = dict[current_code].match_len - 1; > + tmp_code = dict[current_code].char_code; > + buff[offset] = tmp_code; > + count++; > + } > + current_code = dict[current_code].parent_code; > + if ((current_code < 0) || (current_code > (DIC_INDEX_MAX - 1))) { > + av_log(NULL, AV_LOG_ERROR, "MLZ dic index error.\n"); it would be ideal if all av_log() would have a context instead of NULL [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB If you fake or manipulate statistics in a paper in physics you will never get a job again. If you fake or manipulate statistics in a paper in medicin you will get a job for life at the pharma industry.
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