RepoMirrors/ffmpeg
1
0
Fork 0
mirror of https://git.ffmpeg.org/ffmpeg.git synced 2025-01-22 15:23:42 +00:00
Code Issues Projects Releases Wiki Activity

Frame erasure support for fixed-codebook vectors

Browse Source
This commit is contained in:
Vladimir Voroshilov 2009-06-05 10:35:11 +07:00 committed by Michael Niedermayer
parent 9297c7822f
commit 7fadc0151c
1 changed files with 13 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
libavcodec/g729dec.c
View File

@ -97,6 +97,7 @@ typedef struct {
int16_t lsp_buf[2][10]; ///< (0.15) LSP coefficients (previous and current frames) (3.2.5)
int16_t *lsp[2]; ///< pointers to lsp_buf
uint16_t rand_value; ///< random number generator value (4.4.4)
int ma_predictor_prev; ///< switched MA predictor of LSP quantizer from last good frame
} G729Context;
@ -224,6 +225,9 @@ static av_cold int decoder_init(AVCodecContext * avctx)
ctx->lsp[1] = ctx->lsp_buf[1];
memcpy(ctx->lsp[0], lsp_init, 10 * sizeof(int16_t));
/* random seed initialization */
ctx->rand_value = 21845;
return 0;
}
@ -336,6 +340,15 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
/* Round pitch delay to nearest (used everywhere except ff_acelp_interpolate). */
pitch_delay_int = (pitch_delay_3x + 1) / 3;
if (frame_erasure) {
ctx->rand_value = g729_prng(ctx->rand_value);
fc_indexes = ctx->rand_value & ((1 << format.fc_indexes_bits) - 1);
ctx->rand_value = g729_prng(ctx->rand_value);
pulses_signs = ctx->rand_value;
}
memset(fc, 0, sizeof(int16_t) * SUBFRAME_SIZE);
switch (packet_type) {
case FORMAT_G729_8K: