Author: thilo.borgmann
Date: Sat Nov 7 23:58:55 2009
New Revision: 5430
Log:
Add Multi-Channel Correlation decoding.
Introduce ALSChannelData.
Modified:
als/als_data.h
als/alsdec.c
Modified: als/als_data.h
==============================================================================
--- als/als_data.h Sat Nov 7 23:51:02 2009 (r5429)
+++ als/als_data.h Sat Nov 7 23:58:55 2009 (r5430)
@@ -99,4 +99,14 @@ static const uint8_t ltp_gain_values []
0, 8, 16, 24, 32, 40, 48, 56, 64, 70, 76, 82, 88, 92, 96, 100
};
+
+/** Inter-channel weighting factors for multi-channel correlation.
+ * To be indexed by the Rice coded indices.
+ */
+static const int mcc_weightings[] = {
+ 204, 192, 179, 166, 153, 140, 128, 115,
+ 102, 89, 76, 64, 51, 38, 25, 12,
+ 0, -12, -25, -38, -51, -64, -76, -89,
+ -102, -115, -128, -140, -153, -166, -179, -192
+};
#endif /* AVCODEC_ALS_DATA_H */
Modified: als/alsdec.c
==============================================================================
--- als/alsdec.c Sat Nov 7 23:51:02 2009 (r5429)
+++ als/alsdec.c Sat Nov 7 23:58:55 2009 (r5430)
@@ -70,6 +70,16 @@ typedef struct {
typedef struct {
+ int stop_flag;
+ int master_channel;
+ int time_diff_flag;
+ int time_diff_sign;
+ int time_diff_index;
+ int weighting[6];
+} ALSChannelData;
+
+
+typedef struct {
AVCodecContext *avctx;
ALSSpecificConfig sconf;
GetBitContext gb;
@@ -80,8 +90,12 @@ typedef struct {
unsigned int js_switch; ///< if true, joint-stereo decoding is enforced
unsigned int num_blocks; ///< number of blocks used in the current frame
int ltp_lag_length; ///< number of bits used for ltp lag value
- int32_t *quant_cof; ///< quantized parcor coefficients
- int32_t *lpc_cof; ///< coefficients of the direct form prediction filter
+ int32_t **quant_cof; ///< quantized parcor coefficients for a channel
+ int32_t *quant_cof_buffer; ///< contains all quantized parcor coefficients
+ int32_t **lpc_cof; ///< coefficients of the direct form prediction filter for a channel
+ int32_t *lpc_cof_buffer; ///< contains all coefficients of the direct form prediction filter
+ ALSChannelData **chan_data; ///< channel data for multi-channel correlation
+ ALSChannelData *chan_data_buffer; ///< contains channel data for all channels
int32_t *prev_raw_samples; ///< contains unshifted raw samples from the previous block
int32_t **raw_samples; ///< decoded raw samples for each channel
int32_t *raw_buffer; ///< contains all decoded raw samples including carryover samples
@@ -155,7 +169,7 @@ static av_cold int read_specific_config(
{
GetBitContext gb;
uint64_t ht_size;
- int i, config_offset, crc_enabled;
+ int i, config_offset, crc_enabled, n;
MPEG4AudioConfig m4ac;
ALSSpecificConfig *sconf = &ctx->sconf;
AVCodecContext *avctx = ctx->avctx;
@@ -212,11 +226,26 @@ static av_cold int read_specific_config(
ctx->cur_frame_length = sconf->frame_length;
// allocate quantized parcor coefficient buffer
- if (!(ctx->quant_cof = av_malloc(sizeof(*ctx->quant_cof) * sconf->max_order)) ||
- !(ctx->lpc_cof = av_malloc(sizeof(*ctx->lpc_cof) * sconf->max_order))) {
+ n = sconf->mc_coding ? avctx->channels : 1;
+ i = n * sconf->max_order;
+
+ ctx->quant_cof = av_malloc(sizeof(*ctx->quant_cof) * avctx->channels);
+ ctx->lpc_cof = av_malloc(sizeof(*ctx->lpc_cof) * avctx->channels);
+ ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) * i);
+ ctx->lpc_cof_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) * i);
+
+ if (!ctx->quant_cof || !ctx->lpc_cof ||
+ !ctx->quant_cof_buffer || !ctx->lpc_cof_buffer) {
av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
return AVERROR(ENOMEM);
}
+
+ // assign quantized parcor coefficient buffers
+ for (i = 0; i < n; i++) {
+ ctx->quant_cof[i] = ctx->quant_cof_buffer + i * sconf->max_order;
+ ctx->lpc_cof[i] = ctx->lpc_cof_buffer + i * sconf->max_order;
+ }
+
// calculate total number of frames to decode if possible
if (samples != 0xFFFFFFFF) {
ctx->num_frames = (samples - 1) / sconf->frame_length + 1;
@@ -312,7 +341,6 @@ static int check_specific_config(ALSDecC
MISSING_ERR(sconf->floating, "Floating point decoding", -1);
MISSING_ERR(sconf->bgmc, "BGMC entropy decoding", -1);
- MISSING_ERR(sconf->mc_coding, "Multi-channel correlation", -1);
MISSING_ERR(sconf->rlslms, "Adaptive RLS-LMS prediction", -1);
MISSING_ERR(sconf->chan_sort, "Channel sorting", 0);
@@ -801,8 +829,8 @@ static int decode_blocks_ind(ALSDecConte
memset(&bd, 0, sizeof(ALSBlockData));
bd.ra_block = ra_frame;
- bd.quant_cof = ctx->quant_cof;
- bd.lpc_cof = ctx->lpc_cof;
+ bd.quant_cof = ctx->quant_cof[0];
+ bd.lpc_cof = ctx->lpc_cof[0];
bd.prev_raw_samples = ctx->prev_raw_samples;
bd.raw_samples = ctx->raw_samples[c];
@@ -841,14 +869,14 @@ static int decode_blocks(ALSDecContext *
memset(bd, 0, 2 * sizeof(ALSBlockData));
bd[0].ra_block = ra_frame;
- bd[0].quant_cof = ctx->quant_cof;
- bd[0].lpc_cof = ctx->lpc_cof;
+ bd[0].quant_cof = ctx->quant_cof[0];
+ bd[0].lpc_cof = ctx->lpc_cof[0];
bd[0].prev_raw_samples = ctx->prev_raw_samples;
bd[0].js_blocks = *js_blocks;
bd[1].ra_block = ra_frame;
- bd[1].quant_cof = ctx->quant_cof;
- bd[1].lpc_cof = ctx->lpc_cof;
+ bd[1].quant_cof = ctx->quant_cof[0];
+ bd[1].lpc_cof = ctx->lpc_cof[0];
bd[1].prev_raw_samples = ctx->prev_raw_samples;
bd[1].js_blocks = *(js_blocks + 1);
@@ -903,6 +931,108 @@ static int decode_blocks(ALSDecContext *
}
+/** Reads the channel data
+ */
+static void read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c) // replace "current" by "cd"
+{
+ GetBitContext *gb = &ctx->gb;
+ ALSChannelData *current = cd;
+
+ while (!(current->stop_flag = get_bits1(gb))) {
+ current->master_channel = get_bits_long(gb, av_ceil_log2(ctx->avctx->channels));
+
+ if (current->master_channel != c) {
+ current->time_diff_flag = get_bits1(gb);
+ current->weighting[0] = mcc_weightings[decode_rice(gb, 1) + 16];
+ current->weighting[1] = mcc_weightings[decode_rice(gb, 2) + 14];
+ current->weighting[2] = mcc_weightings[decode_rice(gb, 1) + 16];
+
+ if (current->time_diff_flag) {
+ current->weighting[3] = mcc_weightings[decode_rice(gb, 1) + 16];
+ current->weighting[4] = mcc_weightings[decode_rice(gb, 1) + 16];
+ current->weighting[5] = mcc_weightings[decode_rice(gb, 1) + 16];
+
+ current->time_diff_sign = get_bits1(gb);
+ current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
+ if (current->time_diff_sign)
+ current->time_diff_index = -current->time_diff_index;
+ }
+ }
+
+ current++;
+ }
+
+ align_get_bits(gb);
+}
+
+
+static void revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
+ ALSChannelData **cd, int *reverted,
+ unsigned int offset, int c)
+{
+ ALSChannelData *ch = cd[c];
+ unsigned int dep = 0;
+
+ if (reverted[c])
+ return;
+
+ while (!ch[dep].stop_flag) {
+ if (!reverted[ch[dep].master_channel])
+ revert_channel_correlation(ctx, bd, cd, reverted, offset,
+ ch[dep].master_channel);
+
+ dep++;
+ }
+
+ bd->lpc_cof = ctx->lpc_cof[c];
+ bd->quant_cof = ctx->quant_cof[c];
+ bd->raw_samples = ctx->raw_samples[c] + offset;
+
+ dep = 0;
+ while (!ch[dep].stop_flag) {
+ unsigned int smp;
+ unsigned int begin = 1;
+ unsigned int end = bd->block_length - 1;
+ int64_t y;
+ int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
+
+ if (ch[dep].time_diff_flag) {
+ int t = ch[dep].time_diff_index;
+
+ if (ch[dep].time_diff_sign)
+ begin -= t;
+ else
+ end -= t;
+
+ for (smp = begin; smp < end; smp++) {
+ y = (1 << 6) +
+ MUL64(ch[dep].weighting[0], master[smp - 1 ]) +
+ MUL64(ch[dep].weighting[1], master[smp ]) +
+ MUL64(ch[dep].weighting[2], master[smp + 1 ]) +
+ MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
+ MUL64(ch[dep].weighting[4], master[smp + t]) +
+ MUL64(ch[dep].weighting[5], master[smp + 1 + t]);
+
+ bd->raw_samples[smp] += y >> 7;
+ }
+ } else {
+ for (smp = begin; smp < end; smp++) {
+ y = (1 << 6) +
+ MUL64(ch[dep].weighting[0], master[smp - 1]) +
+ MUL64(ch[dep].weighting[1], master[smp ]) +
+ MUL64(ch[dep].weighting[2], master[smp + 1]);
+
+ bd->raw_samples[smp] += y >> 7;
+ }
+ }
+
+ dep++;
+ }
+
+ reverted[c] = 1;
+}
+
+
/** Reads the frame data.
*/
static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
@@ -911,7 +1041,7 @@ static int read_frame_data(ALSDecContext
AVCodecContext *avctx = ctx->avctx;
GetBitContext *gb = &ctx->gb;
unsigned int div_blocks[32]; ///< block sizes.
- unsigned int c;
+ unsigned int b, c;
unsigned int js_blocks[2];
uint32_t bs_info = 0;
@@ -963,13 +1093,53 @@ static int read_frame_data(ALSDecContext
sizeof(*ctx->raw_samples[c]) * sconf->max_order);
}
} else { // multi-channel coding
+ ALSBlockData bd;
+ int reverted_channels[avctx->channels];
+ unsigned int offset = 0;
+
+ memset(&bd, 0, sizeof(ALSBlockData));
+ memset(&reverted_channels, 0, sizeof(int) * avctx->channels);
+
+ bd.ra_block = ra_frame;
+ bd.prev_raw_samples = ctx->prev_raw_samples;
+
get_block_sizes(ctx, div_blocks, &bs_info);
- // TODO: multi channel coding might use a temporary buffer instead as
- // the actual channel is not known when read_block-data is called
- if (decode_blocks_ind(ctx, ra_frame, 0, div_blocks, js_blocks))
- return -1;
- // TODO: read_channel_data
+ for (b = 0; b < ctx->num_blocks; b++) {
+ bd.shift_lsbs = 0;
+ bd.block_length = div_blocks[b];
+
+ for (c = 0; c < avctx->channels; c++) {
+ bd.lpc_cof = ctx->lpc_cof[c];
+ bd.quant_cof = ctx->quant_cof[c];
+ bd.raw_samples = ctx->raw_samples[c] + offset;
+ bd.raw_other = NULL;
+
+ read_block(ctx, &bd);
+ read_channel_data(ctx, ctx->chan_data[c], c);
+ }
+
+ for (c = 0; c < avctx->channels; c++)
+ revert_channel_correlation(ctx, &bd, ctx->chan_data,
+ reverted_channels, offset, c);
+
+ for (c = 0; c < avctx->channels; c++) {
+ bd.lpc_cof = ctx->lpc_cof[c];
+ bd.quant_cof = ctx->quant_cof[c];
+ bd.raw_samples = ctx->raw_samples[c] + offset;
+ decode_block(ctx, &bd);
+ }
+
+ memset(&reverted_channels, 0, avctx->channels * sizeof(int));
+ offset += div_blocks[b];
+ bd.ra_block = 0;
+ }
+
+ // store carryover raw samples
+ for (c = 0; c < avctx->channels; c++)
+ memmove(ctx->raw_samples[c] - sconf->max_order,
+ ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
+ sizeof(*ctx->raw_samples[c]) * sconf->max_order);
}
// TODO: read_diff_float_data
@@ -1054,10 +1224,17 @@ static av_cold int decode_end(AVCodecCon
av_freep(&ctx->quant_cof);
av_freep(&ctx->lpc_cof);
+ av_freep(&ctx->quant_cof_buffer);
+ av_freep(&ctx->lpc_cof_buffer);
av_freep(&ctx->prev_raw_samples);
av_freep(&ctx->raw_samples);
av_freep(&ctx->raw_buffer);
+ if (ctx->sconf.mc_coding) {
+ av_freep(&ctx->chan_data);
+ av_freep(&ctx->chan_data_buffer);
+ }
+
return 0;
}
@@ -1105,6 +1282,27 @@ static av_cold int decode_init(AVCodecCo
else
ctx->ltp_lag_length = 8;
+ // allocate and assign channel data buffer for mcc mode
+ if (sconf->mc_coding) {
+ ctx->chan_data_buffer = av_malloc(sizeof(*ctx->chan_data_buffer) *
+ avctx->channels);
+ ctx->chan_data = av_malloc(sizeof(ALSChannelData) *
+ avctx->channels);
+
+ if (!ctx->chan_data_buffer || !ctx->chan_data) {
+ av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
+ decode_end(avctx);
+ return AVERROR(ENOMEM);
+ }
+
+ for (c = 0; c < avctx->channels; c++)
+ ctx->chan_data[c] = ctx->chan_data_buffer +
+ c * sizeof(ALSChannelData);
+ } else {
+ ctx->chan_data = NULL;
+ ctx->chan_data_buffer = NULL;
+ }
+
avctx->frame_size = sconf->frame_length;
channel_size = sconf->frame_length + sconf->max_order;
