November 2009 - FFmpeg-soc - lists.ffmpeg.org

[PATCH]aacsbr: Run SBR in pure upsampling mode until we get an SBR header
by Alex Converse 20 Nov '09

20 Nov '09

We need information from the header to decode the sbr frame data.

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[PATCH]aacsbr: bs_amp_res is overridden by 0 for (bs_frame_class == FIXFIX && bs_num_env == 1) only for the current frame
by Alex Converse 20 Nov '09

20 Nov '09

So this is kind of ambiguous in the spec... bs_amp_res is read in the SBR header. If (bs_frame_class == FIXFIX && bs_num_env == 1) bs_amp_res is set to zero. Those are both per frame variables and I'm pretty sure the affect only lasts for one frame. That's how the refdec seems to behave anyway. 4.B.18.6 Data quantization The spectral envelope scalefactors are quantized in 3dB steps or in 1.5dB steps, dependent on the time frequency resolution of the current SBR frame, and bs_amp_res. For the case where there is only one SBR envelope per SBR frame and of SBR frame class FIXFIX, 1.5 dB steps are always used, disregarded the value of bs_amp_res.

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[soc]: r5455 - aac-sbr/aacsbr.c
by alexc 20 Nov '09

20 Nov '09

Author: alexc Date: Fri Nov 20 21:32:14 2009 New Revision: 5455 Log: Cosmetics: reindent Modified: aac-sbr/aacsbr.c Modified: aac-sbr/aacsbr.c ============================================================================== --- aac-sbr/aacsbr.c Fri Nov 20 21:29:01 2009 (r5454) +++ aac-sbr/aacsbr.c Fri Nov 20 21:32:14 2009 (r5455) @@ -659,7 +659,7 @@ static void sbr_noise(SpectralBandReplic for (i = 0; i < ch_data->bs_num_noise; i++) { if (!ch_data->bs_df_noise[i]) { - ch_data->bs_data_noise[i][0] = get_bits(gb, 5); // bs_noise_start_value_balance or bs_noise_start_value_level + ch_data->bs_data_noise[i][0] = get_bits(gb, 5); // bs_noise_start_value_balance or bs_noise_start_value_level for (j = 1; j < sbr->n_q; j++) ch_data->bs_data_noise[i][j] = get_vlc2(gb, f_huff, 9, max_depth + 1); } else {

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[soc]: r5454 - in aac-sbr: aacsbr.c aacsbr.h
by alexc 20 Nov '09

20 Nov '09

Author: alexc Date: Fri Nov 20 21:29:01 2009 New Revision: 5454 Log: bs_amp_res is overridden by 0 for (bs_frame_class == FIXFIX && bs_num_env == 1) only for the current frame. Modified: aac-sbr/aacsbr.c aac-sbr/aacsbr.h Modified: aac-sbr/aacsbr.c ============================================================================== --- aac-sbr/aacsbr.c Fri Nov 20 21:28:59 2009 (r5453) +++ aac-sbr/aacsbr.c Fri Nov 20 21:29:01 2009 (r5454) @@ -85,7 +85,7 @@ static unsigned int sbr_header(SpectralB // Save last spectrum parameters variables to compare to new ones memcpy(&sbr->spectrum_params[0], &sbr->spectrum_params[1], sizeof(SpectrumParameters)); - sbr->bs_amp_res = get_bits1(gb); + sbr->bs_amp_res_header = get_bits1(gb); sbr->spectrum_params[1].bs_start_freq = get_bits(gb, 4); sbr->spectrum_params[1].bs_stop_freq = get_bits(gb, 4); sbr->spectrum_params[1].bs_xover_band = get_bits(gb, 3); @@ -501,6 +501,7 @@ static int sbr_grid(AACContext *ac, Spec int i; ch_data->bs_num_env[0] = ch_data->bs_num_env[1]; + sbr->bs_amp_res = sbr->bs_amp_res_header; switch (ch_data->bs_frame_class = get_bits(gb, 2)) { case FIXFIX: Modified: aac-sbr/aacsbr.h ============================================================================== --- aac-sbr/aacsbr.h Fri Nov 20 21:28:59 2009 (r5453) +++ aac-sbr/aacsbr.h Fri Nov 20 21:29:01 2009 (r5454) @@ -109,6 +109,7 @@ typedef struct { uint8_t start; // SBR header bitstream variables uint8_t bs_amp_res; + uint8_t bs_amp_res_header; SpectrumParameters spectrum_params[2]; // if (bs_header_extra_2) uint8_t bs_limiter_bands;

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[soc]: r5453 - in aac-sbr: aacsbr.c aacsbr.h
by alexc 20 Nov '09

20 Nov '09

Author: alexc Date: Fri Nov 20 21:28:59 2009 New Revision: 5453 Log: Run SBR in pure upsampling mode until we get an SBR header. Modified: aac-sbr/aacsbr.c aac-sbr/aacsbr.h Modified: aac-sbr/aacsbr.c ============================================================================== --- aac-sbr/aacsbr.c Fri Nov 20 21:28:57 2009 (r5452) +++ aac-sbr/aacsbr.c Fri Nov 20 21:28:59 2009 (r5453) @@ -80,6 +80,8 @@ static unsigned int sbr_header(SpectralB uint8_t bs_header_extra_1; uint8_t bs_header_extra_2; + sbr->start = 1; + // Save last spectrum parameters variables to compare to new ones memcpy(&sbr->spectrum_params[0], &sbr->spectrum_params[1], sizeof(SpectrumParameters)); @@ -805,6 +807,7 @@ int ff_decode_sbr_extension(AACContext * if (sbr->reset) sbr_reset(ac, sbr); + if (sbr->start) num_sbr_bits += sbr_data(ac, sbr, gb, id_aac); num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7; Modified: aac-sbr/aacsbr.h ============================================================================== --- aac-sbr/aacsbr.h Fri Nov 20 21:28:57 2009 (r5452) +++ aac-sbr/aacsbr.h Fri Nov 20 21:28:59 2009 (r5453) @@ -106,6 +106,7 @@ typedef struct { * Spectral Band Replication */ typedef struct { + uint8_t start; // SBR header bitstream variables uint8_t bs_amp_res; SpectrumParameters spectrum_params[2];

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[soc]: r5452 - aac-sbr/aacsbr.c
by alexc 20 Nov '09

20 Nov '09

Author: alexc Date: Fri Nov 20 21:28:57 2009 New Revision: 5452 Log: Read bs_noise_start_value_level when !(bs_coupling && ch) Modified: aac-sbr/aacsbr.c Modified: aac-sbr/aacsbr.c ============================================================================== --- aac-sbr/aacsbr.c Fri Nov 20 21:28:56 2009 (r5451) +++ aac-sbr/aacsbr.c Fri Nov 20 21:28:57 2009 (r5452) @@ -656,7 +656,6 @@ static void sbr_noise(SpectralBandReplic for (i = 0; i < ch_data->bs_num_noise; i++) { if (!ch_data->bs_df_noise[i]) { - if (sbr->bs_coupling && ch) ch_data->bs_data_noise[i][0] = get_bits(gb, 5); // bs_noise_start_value_balance or bs_noise_start_value_level for (j = 1; j < sbr->n_q; j++) ch_data->bs_data_noise[i][j] = get_vlc2(gb, f_huff, 9, max_depth + 1);

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[soc]: r5451 - aac-sbr/aacsbr.c
by alexc 20 Nov '09

20 Nov '09

Author: alexc Date: Fri Nov 20 21:28:56 2009 New Revision: 5451 Log: NINT as specified in 14496-3 is always round away from zero. This matches the behavior of lroundf not lrintf. In some cases we land exactly at a number ending in .5 and therefore this distinction is important. Modified: aac-sbr/aacsbr.c Modified: aac-sbr/aacsbr.c ============================================================================== --- aac-sbr/aacsbr.c Fri Nov 20 21:28:54 2009 (r5450) +++ aac-sbr/aacsbr.c Fri Nov 20 21:28:56 2009 (r5451) @@ -152,8 +152,8 @@ static int sbr_make_f_master(AACContext } else temp = 5000; - start_min = (unsigned int)lrintf((temp << 7) / (float)ac->m4ac.ext_sample_rate); - stop_min = (unsigned int)lrintf((temp << 8) / (float)ac->m4ac.ext_sample_rate); + start_min = (unsigned int)lroundf((temp << 7) / (float)ac->m4ac.ext_sample_rate); + stop_min = (unsigned int)lroundf((temp << 8) / (float)ac->m4ac.ext_sample_rate); if (ac->m4ac.ext_sample_rate == 16000) { sbr_offset_ptr = sbr_offset[0]; @@ -178,8 +178,8 @@ static int sbr_make_f_master(AACContext if (spectrum->bs_stop_freq < 14) { sbr->k[2] = stop_min; for (k = 0; k < spectrum->bs_stop_freq; k++) { - sbr->k[2] += lrintf(stop_min * powf(64.0f / (float)stop_min, (k + 1) / 13.0f)) - - lrintf(stop_min * powf(64.0f / (float)stop_min, k / 13.0f)); + sbr->k[2] += lroundf(stop_min * powf(64.0f / (float)stop_min, (k + 1) / 13.0f)) - + lroundf(stop_min * powf(64.0f / (float)stop_min, k / 13.0f)); } } else if (spectrum->bs_stop_freq == 14) { sbr->k[2] = 2*sbr->k[0]; @@ -200,7 +200,7 @@ static int sbr_make_f_master(AACContext sbr->n_master = ((unsigned int)((sbr->k[2] - sbr->k[0]) / (float)(dk << 1))) << 1; } else { dk = 2; - sbr->n_master = lrintf((sbr->k[2] - sbr->k[0]) / (float)(dk << 1)) << 1; + sbr->n_master = lroundf((sbr->k[2] - sbr->k[0]) / (float)(dk << 1)) << 1; } for (k = 1; k <= sbr->n_master; k++) @@ -248,7 +248,7 @@ static int sbr_make_f_master(AACContext sbr->k[1] = sbr->k[2]; } - num_bands_0 = lrintf(bands * logf(sbr->k[1] / (float)sbr->k[0]) / (2.0f * logf(2.0f))) << 1; + num_bands_0 = lroundf(bands * logf(sbr->k[1] / (float)sbr->k[0]) / (2.0f * logf(2.0f))) << 1; if (num_bands_0 <= 0) { // Requirements (14496-3 sp04 p205) av_log(ac->avccontext, AV_LOG_ERROR, "Invalid num_bands_0: %d\n", num_bands_0); @@ -259,8 +259,8 @@ static int sbr_make_f_master(AACContext vk0[0] = 0; for (k = 0; k < num_bands_0; k++) { - vk0[k + 1] = lrintf(sbr->k[0] * powf(sbr->k[1] / (float)sbr->k[0], (k + 1) / (float)num_bands_0)) - - lrintf(sbr->k[0] * powf(sbr->k[1] / (float)sbr->k[0], k / (float)num_bands_0)); + vk0[k + 1] = lroundf(sbr->k[0] * powf(sbr->k[1] / (float)sbr->k[0], (k + 1) / (float)num_bands_0)) - + lroundf(sbr->k[0] * powf(sbr->k[1] / (float)sbr->k[0], k / (float)num_bands_0)); } qsort(vk0 + 1, num_bands_0, sizeof(vk0[1]), qsort_comparison_function); @@ -277,14 +277,14 @@ static int sbr_make_f_master(AACContext if (two_regions) { int *vk1; - unsigned int num_bands_1 = lrintf(bands * logf(sbr->k[2] / (float)sbr->k[1]) / + unsigned int num_bands_1 = lroundf(bands * logf(sbr->k[2] / (float)sbr->k[1]) / (2.0f * logf(2.0f) * warp)) << 1; vk1 = av_malloc((num_bands_1 + 1) * sizeof(int)); for (k = 0; k < num_bands_1; k++) { - vk1[k + 1] = lrintf(sbr->k[1] * powf(sbr->k[2] / (float)sbr->k[1], (k + 1) / (float)num_bands_1)) - - lrintf(sbr->k[1] * powf(sbr->k[2] / (float)sbr->k[1], k / (float)num_bands_1)); + vk1[k + 1] = lroundf(sbr->k[1] * powf(sbr->k[2] / (float)sbr->k[1], (k + 1) / (float)num_bands_1)) - + lroundf(sbr->k[1] * powf(sbr->k[2] / (float)sbr->k[1], k / (float)num_bands_1)); } vdk1_min = array_min_int(vk1 + 1, num_bands_1); @@ -348,7 +348,7 @@ static int sbr_hf_calc_npatches(AACConte int i, k, sb = 0; int msb = sbr->k[0]; int usb = sbr->k[3]; - int goal_sb = lrintf((1 << 11) * 1000 / (float)ac->m4ac.sample_rate); + int goal_sb = lroundf((1 << 11) * 1000 / (float)ac->m4ac.sample_rate); sbr->num_patches = 0; @@ -435,7 +435,7 @@ static int sbr_make_f_derived(AACContext for (k = 1; k <= sbr->n[0]; k++) sbr->f_tablelow[k] = sbr->f_tablehigh[(k << 1) - temp]; - sbr->n_q = FFMAX(1, lrintf(sbr->spectrum_params[1].bs_noise_bands * logf(sbr->k[2] / (float)sbr->k[3]) / logf(2.0f))); // 0 <= bs_noise_bands <= 3 + sbr->n_q = FFMAX(1, lroundf(sbr->spectrum_params[1].bs_noise_bands * logf(sbr->k[2] / (float)sbr->k[3]) / logf(2.0f))); // 0 <= bs_noise_bands <= 3 if (sbr->n_q > 5) { av_log(ac->avccontext, AV_LOG_ERROR, "Too many noise floor scale factors: %d\n", sbr->n_q); return -1; @@ -841,7 +841,7 @@ static int sbr_time_freq_grid(AACContext sbr->t_env[ch][ch_data->bs_num_env[1]] = abs_bord_trail; if (ch_data->bs_frame_class == FIXFIX) { - unsigned int temp = (unsigned int)lrintf(abs_bord_trail / (float)ch_data->bs_num_env[1]); + unsigned int temp = (unsigned int)lroundf(abs_bord_trail / (float)ch_data->bs_num_env[1]); for (i = 0; i < n_rel_lead; i++) sbr->t_env[ch][i + 1] = sbr->t_env[ch][i] + temp; } else if (ch_data->bs_frame_class > 1) { // VARFIX or VARVAR

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[soc]: r5450 - aac-sbr/aacsbr.c
by alexc 20 Nov '09

20 Nov '09

Author: alexc Date: Fri Nov 20 21:28:54 2009 New Revision: 5450 Log: Replace ceil(log() / M_LN2) with a ceil_log2[] lookup table. The result of this calculation is a number of bits to be read therefore we must be exact. Modified: aac-sbr/aacsbr.c Modified: aac-sbr/aacsbr.c ============================================================================== --- aac-sbr/aacsbr.c Wed Nov 18 13:08:22 2009 (r5449) +++ aac-sbr/aacsbr.c Fri Nov 20 21:28:54 2009 (r5450) @@ -489,6 +489,10 @@ static int sbr_make_f_derived(AACContext return 0; } +static int8_t ceil_log2[] = { + 0, 0, 1, 2, 2, 3, 3, +}; + static int sbr_grid(AACContext *ac, SpectralBandReplication *sbr, GetBitContext *gb, SBRData *ch_data) { @@ -514,7 +518,7 @@ static int sbr_grid(AACContext *ac, Spec for (i = 0; i < ch_data->bs_num_rel[1]; i++) ch_data->bs_rel_bord[1][i] = (get_bits(gb, 2) << 1) + 2; - ch_data->bs_pointer = get_bits(gb, ceil(logf(ch_data->bs_num_env[1] + 1) / M_LN2)); + ch_data->bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env[1] + 1]); for (i = 0; i < ch_data->bs_num_env[1]; i++) ch_data->bs_freq_res[ch_data->bs_num_env[1] - 1 - i] = get_bits1(gb); @@ -527,7 +531,7 @@ static int sbr_grid(AACContext *ac, Spec for (i = 0; i < ch_data->bs_num_rel[0]; i++) ch_data->bs_rel_bord[0][i] = (get_bits(gb, 2) << 1) + 2; - ch_data->bs_pointer = get_bits(gb, ceil(logf(ch_data->bs_num_env[1] + 1) / M_LN2)); + ch_data->bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env[1] + 1]); for (i = 0; i < ch_data->bs_num_env[1]; i++) ch_data->bs_freq_res[i] = get_bits1(gb); @@ -544,7 +548,7 @@ static int sbr_grid(AACContext *ac, Spec for (i = 0; i < ch_data->bs_num_rel[1]; i++) ch_data->bs_rel_bord[1][i] = (get_bits(gb, 2) << 1) + 2; - ch_data->bs_pointer = get_bits(gb, ceil(logf(ch_data->bs_num_env[1] + 1) / M_LN2)); + ch_data->bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env[1] + 1]); for (i = 0; i < ch_data->bs_num_env[1]; i++) ch_data->bs_freq_res[i] = get_bits1(gb);

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AACSBR review: sbr_env_estimate
by Alex Converse 18 Nov '09

18 Nov '09

Diego has been bugging me to do some review of the sbr code in the soc svn so here we go... > // Estimation of current envelope (14496-3 sp04 p218) > static void sbr_env_estimate(float **e_curr, float ***x_high, > SpectralBandReplication *sbr, SBRData *ch_data, > int ch) > { > int i, l, m; > int ilb = sbr->t_env[ch][l] * 2 + ENVELOPE_ADJUSTMENT_OFFSET; > int iub = sbr->t_env[ch][l + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET; Danger Will Robinson, l is not yet defined. > > if (sbr->bs_interpol_freq) { > for (l = 0; l < ch_data->bs_num_env[1]; l++) { > const int env_size = (sbr->t_env[ch][l + 1] - sbr->t_env[ch][l]) << 1; > > for (m = 0; m < sbr->m; m++) { > float sum = 0.0f; > > for (i = ilb; i < iub; i++) { > sum += x_high[m + sbr->k[3]][i][0] * x_high[m + sbr->k[3]][i][0] + > x_high[m + sbr->k[3]][i][1] * x_high[m + sbr->k[3]][i][1]; > } > e_curr[l][m] = sum / env_size; > } > } > } else { > int k, p; > > for (l = 0; l < ch_data->bs_num_env[1]; l++) { > const int env_size = (sbr->t_env[ch][l + 1] - sbr->t_env[ch][l]) << 1; > const uint16_t *table = ch_data->bs_freq_res[l + 1] ? sbr->f_tablehigh : sbr->f_tablelow; > > for (p = 0; p < sbr->n[ch_data->bs_freq_res[l + 1]]; p++) { > float sum = 0.0f; > const int den = env_size * (table[p + 1] - table[p] + 1); > > for (k = table[p]; k < table[p + 1]; k++) { > for (i = ilb; i < iub; i++) { > sum += x_high[k][i][0] * x_high[k][i][0] + > x_high[k][i][1] * x_high[k][i][1]; > } > e_curr[l][k - sbr->k[3]] = sum / den; > } > } > } > } > } >

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[PATCH] aacsbr: sbr_header default values
by Alex Converse 18 Nov '09

18 Nov '09

Both bs_header_extra_1 and bs_header_extra_2 are marked with Note 3. Note 3: If this bit is not set the default values for the underlying data elements shall be used disregarded any previous value.

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