Author: thilo.borgmann Date: Fri Jul 31 01:27:40 2009 New Revision: 4845 Log: Added functionality for joint-stereo decoding. Modified: als/alsdec.c Modified: als/alsdec.c ============================================================================== --- als/alsdec.c Fri Jul 31 00:41:54 2009 (r4844) +++ als/alsdec.c Fri Jul 31 01:27:40 2009 (r4845) @@ -358,15 +358,17 @@ static void all_parcor_to_lpc(unsigned i /** Reads the block data. */ static int read_block_data(ALSDecContext *ctx, unsigned int ra_block, - int64_t *raw_samples, unsigned int block_length) + int64_t *raw_samples, unsigned int block_length, + uint32_t *js_blocks) { ALSSpecificConfig *sconf = &ctx->sconf; AVCodecContext *avctx = ctx->avctx; GetBitContext *gb = &ctx->gb; unsigned int block_type; - unsigned int js_block; unsigned int k; + *js_blocks <<= 1; + // read block type block_type = get_bits1(gb); @@ -375,7 +377,7 @@ static int read_block_data(ALSDecContext int32_t const_val = 0; const_block = get_bits1(gb); // 1 = constant value, 0 = zero block (silence) - js_block = get_bits1(gb); + *js_blocks |= get_bits1(gb); // skip 5 reserved bits skip_bits(gb, 5); @@ -406,8 +408,7 @@ static int read_block_data(ALSDecContext int64_t *res = ctx->residuals; unsigned int sb, smp; - - js_block = get_bits1(gb); + *js_blocks |= get_bits1(gb); // Determine the number of sub blocks for entropy decoding if (!sconf->bgmc_mode && !sconf->sb_part) @@ -600,6 +601,7 @@ static int read_frame_data(ALSDecContext unsigned int div_blocks[32]; ///< Block sizes. unsigned int c, b, ra_block, block_length; int64_t *raw_samples; + uint32_t js_blocks[2]; uint32_t bs_info = 0; unsigned int *ptr_div_blocks = &div_blocks[0]; @@ -617,6 +619,9 @@ static int read_frame_data(ALSDecContext int independent_bs = !sconf->joint_stereo; for (c = 0; c < sconf->channels; c++) { + js_blocks[0] = 0; + js_blocks[1] = 0; + if (sconf->block_switching) { unsigned int bs_info_len = 1 << (sconf->block_switching + 2); bs_info = get_bits_long(gb, bs_info_len); @@ -641,7 +646,7 @@ static int read_frame_data(ALSDecContext for (b = 0; b < ctx->num_blocks; b++) { ra_block = !b && ra_frame; block_length = sconf->frame_length >> div_blocks[b]; - read_block_data(ctx, ra_block, raw_samples, block_length); + read_block_data(ctx, ra_block, raw_samples, block_length, &js_blocks[0]); raw_samples += block_length; } } else { @@ -652,14 +657,48 @@ static int read_frame_data(ALSDecContext block_length = sconf->frame_length >> div_blocks[b]; raw_samples = ctx->raw_samples[c] + offset; - read_block_data(ctx, ra_block, raw_samples, block_length); + read_block_data(ctx, ra_block, raw_samples, block_length, &js_blocks[0]); raw_samples = ctx->raw_samples[c + 1] + offset; - read_block_data(ctx, ra_block, raw_samples, block_length); + read_block_data(ctx, ra_block, raw_samples, block_length, &js_blocks[1]); offset += block_length; } c++; + + if (js_blocks[0] || js_blocks[1]) { + int64_t *raw_samples_L, *raw_samples_R; + unsigned int s; + b = ctx->num_blocks - 1; + + raw_samples_L = ctx->raw_samples[c - 1] + sconf->frame_length; + raw_samples_R = ctx->raw_samples[c ] + sconf->frame_length; + + while (js_blocks[0] || js_blocks[1]) { + unsigned int LD, RD; + block_length = sconf->frame_length >> div_blocks[b]; + raw_samples_L -= block_length; + raw_samples_R -= block_length; + + LD = js_blocks[0] & 1; + RD = js_blocks[1] & 1; + + if (LD) { // L = R - D + if (RD) + av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair!"); + + for (s = 0; s < block_length; s++) + raw_samples_L[s] = raw_samples_R[s] - raw_samples_L[s]; + } else if (RD) { // R = D + L + for (s = 0; s < block_length; s++) + raw_samples_R[s] = raw_samples_R[s] + raw_samples_L[s]; + } + + b--; + js_blocks[0] >>= 1; + js_blocks[1] >>= 1; + } + } } } } else { @@ -679,7 +718,7 @@ static int read_frame_data(ALSDecContext for (b = 0; b < ctx->num_blocks; b++) { ra_block = !b && ra_frame; block_length = sconf->frame_length >> div_blocks[b]; - read_block_data(ctx, ra_block, raw_samples, block_length); + read_block_data(ctx, ra_block, raw_samples, block_length, &js_blocks[0]); raw_samples += block_length; // TODO: read_channel_data }