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Code Issues Releases Activity

Import more OKed parts of ALAC encoder from GSoC repo.

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Originally committed as revision 14843 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Ramiro Polla 2008-08-19 16:07:58 +00:00
parent c89cb5894e
commit 0d962ecb70
1 changed files with 98 additions and 0 deletions
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98
libavcodec/alacenc.c
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@ -38,6 +38,11 @@
#define ALAC_MAX_LPC_PRECISION 9
#define ALAC_MAX_LPC_SHIFT 9
#define ALAC_CHMODE_LEFT_RIGHT 0
#define ALAC_CHMODE_LEFT_SIDE 1
#define ALAC_CHMODE_RIGHT_SIDE 2
#define ALAC_CHMODE_MID_SIDE 3
typedef struct RiceContext {
int history_mult;
int initial_history;
@ -53,9 +58,12 @@ typedef struct LPCContext {
typedef struct AlacEncodeContext {
int compression_level;
int min_prediction_order;
int max_prediction_order;
int max_coded_frame_size;
int write_sample_size;
int32_t sample_buf[MAX_CHANNELS][DEFAULT_FRAME_SIZE];
int32_t predictor_buf[DEFAULT_FRAME_SIZE];
int interlacing_shift;
int interlacing_leftweight;
PutBitContext pbctx;
@ -116,6 +124,20 @@ static void write_frame_header(AlacEncodeContext *s, int is_verbatim)
put_bits(&s->pbctx, 32, s->avctx->frame_size); // No. of samples in the frame
}
static void calc_predictor_params(AlacEncodeContext *s, int ch)
{
int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER];
int shift[MAX_LPC_ORDER];
int opt_order;
opt_order = ff_lpc_calc_coefs(&s->dspctx, s->sample_buf[ch], s->avctx->frame_size, DEFAULT_MIN_PRED_ORDER, DEFAULT_MAX_PRED_ORDER,
ALAC_MAX_LPC_PRECISION, coefs, shift, 1, ORDER_METHOD_EST, ALAC_MAX_LPC_SHIFT, 1);
s->lpc[ch].lpc_order = opt_order;
s->lpc[ch].lpc_quant = shift[opt_order-1];
memcpy(s->lpc[ch].lpc_coeff, coefs[opt_order-1], opt_order*sizeof(int));
}
static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n)
{
int i, best;
@ -147,6 +169,53 @@ static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n)
best = i;
}
}
return best;
}
static void alac_stereo_decorrelation(AlacEncodeContext *s)
{
int32_t *left = s->sample_buf[0], *right = s->sample_buf[1];
int i, mode, n = s->avctx->frame_size;
int32_t tmp;
mode = estimate_stereo_mode(left, right, n);
switch(mode)
{
case ALAC_CHMODE_LEFT_RIGHT:
s->interlacing_leftweight = 0;
s->interlacing_shift = 0;
break;
case ALAC_CHMODE_LEFT_SIDE:
for(i=0; i<n; i++) {
right[i] = left[i] - right[i];
}
s->interlacing_leftweight = 1;
s->interlacing_shift = 0;
break;
case ALAC_CHMODE_RIGHT_SIDE:
for(i=0; i<n; i++) {
tmp = right[i];
right[i] = left[i] - right[i];
left[i] = tmp + (right[i] >> 31);
}
s->interlacing_leftweight = 1;
s->interlacing_shift = 31;
break;
default:
for(i=0; i<n; i++) {
tmp = left[i];
left[i] = (tmp + right[i]) >> 1;
right[i] = tmp - right[i];
}
s->interlacing_leftweight = 1;
s->interlacing_shift = 1;
break;
}
}
static void write_compressed_frame(AlacEncodeContext *s)
{
@ -226,6 +295,32 @@ static av_cold int alac_encode_init(AVCodecContext *avctx)
AV_WB8(alac_extradata+20, s->rc.k_modifier);
}
if(avctx->min_prediction_order >= 0) {
if(avctx->min_prediction_order < MIN_LPC_ORDER ||
avctx->min_prediction_order > MAX_LPC_ORDER) {
av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n", avctx->min_prediction_order);
return -1;
}
s->min_prediction_order = avctx->min_prediction_order;
}
if(avctx->max_prediction_order >= 0) {
if(avctx->max_prediction_order < MIN_LPC_ORDER ||
avctx->max_prediction_order > MAX_LPC_ORDER) {
av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n", avctx->max_prediction_order);
return -1;
}
s->max_prediction_order = avctx->max_prediction_order;
}
if(s->max_prediction_order < s->min_prediction_order) {
av_log(avctx, AV_LOG_ERROR, "invalid prediction orders: min=%d max=%d\n",
s->min_prediction_order, s->max_prediction_order);
return -1;
}
avctx->extradata = alac_extradata;
avctx->extradata_size = ALAC_EXTRADATA_SIZE;
@ -255,6 +350,9 @@ static int alac_encode_frame(AVCodecContext *avctx, uint8_t *frame,
return -1;
}
verbatim:
init_put_bits(pb, frame, buf_size);
if((s->compression_level == 0) || verbatim_flag) {
// Verbatim mode
int16_t *samples = data;