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G.729 decoding routine (skeleton, including parameters decoding).

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Originally committed as revision 19218 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Vladimir Voroshilov 2009-06-18 18:14:38 +00:00
parent 71ee651559
commit 17dbe25438
1 changed files with 92 additions and 21 deletions
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113
libavcodec/g729dec.c
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@ -72,15 +72,32 @@
#define SHARP_MAX 13017
typedef struct {
int sample_rate;
uint8_t packed_frame_size; ///< input frame size(in bytes)
uint8_t unpacked_frame_size;///< output frame size (in bytes)
uint8_t ac_index_bits[2]; ///< adaptive codebook index for second subframe (size in bits)
uint8_t parity_bit; ///< parity bit for pitch delay
uint8_t gc_1st_index_bits; ///< gain codebook (first stage) index (size in bits)
uint8_t gc_2nd_index_bits; ///< gain codebook (second stage) index (size in bits)
uint8_t fc_signs_bits; ///< number of pulses in fixed-codebook vector
uint8_t fc_indexes_bits; ///< size (in bits) of fixed-codebook index entry
/// mr_energy = mean_energy + 10 * log10(2^26 * subframe_size) in (7.13)
int mr_energy;
} G729FormatDescription;
static const G729FormatDescription format_g729_8k = {
.ac_index_bits = {8,5},
.parity_bit = 1,
.gc_1st_index_bits = GC_1ST_IDX_BITS_8K,
.gc_2nd_index_bits = GC_2ND_IDX_BITS_8K,
.fc_signs_bits = 4,
.fc_indexes_bits = 13,
};
static const G729FormatDescription format_g729d_6k4 = {
.ac_index_bits = {8,4},
.parity_bit = 0,
.gc_1st_index_bits = GC_1ST_IDX_BITS_6K4,
.gc_2nd_index_bits = GC_2ND_IDX_BITS_6K4,
.fc_signs_bits = 2,
.fc_indexes_bits = 9,
};
/**
* \brief pseudo random number generator
*/
@ -110,6 +127,64 @@ static av_cold int decoder_init(AVCodecContext * avctx)
return 0;
}
static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
int16_t *out_frame = data;
GetBitContext gb;
G729FormatDescription format;
int frame_erasure = 0; ///< frame erasure detected during decoding
int bad_pitch = 0; ///< parity check failed
int i;
uint8_t ma_predictor; ///< switched MA predictor of LSP quantizer
uint8_t quantizer_1st; ///< first stage vector of quantizer
uint8_t quantizer_2nd_lo; ///< second stage lower vector of quantizer (size in bits)
uint8_t quantizer_2nd_hi; ///< second stage higher vector of quantizer (size in bits)
if (*data_size < SUBFRAME_SIZE << 2) {
av_log(avctx, AV_LOG_ERROR, "Error processing packet: output buffer too small\n");
return AVERROR(EIO);
}
if (buf_size == 10) {
format = format_g729_8k;
av_log(avctx, AV_LOG_DEBUG, "Packet type: %s\n", "G.729 @ 8kbit/s");
} else if (buf_size == 8) {
format = format_g729d_6k4;
av_log(avctx, AV_LOG_DEBUG, "Packet type: %s\n", "G.729D @ 6.4kbit/s");
} else {
av_log(avctx, AV_LOG_ERROR, "Packet size %d is unknown.\n", buf_size);
return (AVERROR_NOFMT);
}
for (i=0; i < buf_size; i++)
frame_erasure |= buf[i];
frame_erasure = !frame_erasure;
init_get_bits(&gb, buf, buf_size);
ma_predictor = get_bits(&gb, 1);
quantizer_1st = get_bits(&gb, VQ_1ST_BITS);
quantizer_2nd_lo = get_bits(&gb, VQ_2ND_BITS);
quantizer_2nd_hi = get_bits(&gb, VQ_2ND_BITS);
for (i = 0; i < 2; i++) {
uint8_t ac_index; ///< adaptive codebook index
uint8_t pulses_signs; ///< fixed-codebook vector pulse signs
int fc_indexes; ///< fixed-codebook indexes
uint8_t gc_1st_index; ///< gain codebook (first stage) index
uint8_t gc_2nd_index; ///< gain codebook (second stage) index
ac_index = get_bits(&gb, format.ac_index_bits[i]);
if(!i && format.parity_bit)
bad_pitch = get_parity(ac_index) == get_bits1(&gb);
fc_indexes = get_bits(&gb, format.fc_indexes_bits);
pulses_signs = get_bits(&gb, format.fc_signs_bits);
gc_1st_index = get_bits(&gb, format.gc_1st_index_bits);
gc_2nd_index = get_bits(&gb, format.gc_2nd_index_bits);
ff_acelp_weighted_vector_sum(fc + pitch_delay_int[i],
fc + pitch_delay_int[i],
fc, 1 << 14,
@ -117,31 +192,27 @@ static av_cold int decoder_init(AVCodecContext * avctx)
0, 14,
SUBFRAME_SIZE - pitch_delay_int[i]);
if (ctx->frame_erasure) {
if (frame_erasure) {
ctx->gain_pitch = (29491 * ctx->gain_pitch) >> 15; // 0.90 (0.15)
ctx->gain_code = ( 2007 * ctx->gain_code ) >> 11; // 0.98 (0.11)
gain_corr_factor = 0;
} else {
ctx->gain_pitch = cb_gain_1st_8k[parm->gc_1st_index[i]][0] +
cb_gain_2nd_8k[parm->gc_2nd_index[i]][0];
gain_corr_factor = cb_gain_1st_8k[parm->gc_1st_index[i]][1] +
cb_gain_2nd_8k[parm->gc_2nd_index[i]][1];
ctx->gain_pitch = cb_gain_1st_8k[gc_1st_index][0] +
cb_gain_2nd_8k[gc_2nd_index][0];
gain_corr_factor = cb_gain_1st_8k[gc_1st_index][1] +
cb_gain_2nd_8k[gc_2nd_index][1];
ff_acelp_weighted_vector_sum(ctx->exc + i * SUBFRAME_SIZE,
ctx->exc + i * SUBFRAME_SIZE, fc,
(!voicing && ctx->frame_erasure) ? 0 : ctx->gain_pitch,
( voicing && ctx->frame_erasure) ? 0 : ctx->gain_code,
(!voicing && frame_erasure) ? 0 : ctx->gain_pitch,
( voicing && frame_erasure) ? 0 : ctx->gain_code,
1 << 13, 14, SUBFRAME_SIZE);
}
if (buf_size < packed_frame_size) {
av_log(avctx, AV_LOG_ERROR, "Error processing packet: packet size too small\n");
return AVERROR(EIO);
}
if (*data_size < unpacked_frame_size) {
av_log(avctx, AV_LOG_ERROR, "Error processing packet: output buffer too small\n");
return AVERROR(EIO);
}
*data_size = SUBFRAME_SIZE << 2;
return buf_size;
}
AVCodec g729_decoder =
{