[FFmpeg-soc] [soc]: r3452 - alacenc/alacenc.c
jai_menon
subversion at mplayerhq.hu
Mon Aug 18 22:18:32 CEST 2008
Author: jai_menon
Date: Mon Aug 18 22:18:32 2008
New Revision: 3452
Log:
sync alacenc soc repo with code currently under review
Modified:
alacenc/alacenc.c
Modified: alacenc/alacenc.c
==============================================================================
--- alacenc/alacenc.c (original)
+++ alacenc/alacenc.c Mon Aug 18 22:18:32 2008
@@ -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;
@@ -52,13 +57,13 @@ typedef struct LPCContext {
} LPCContext;
typedef struct AlacEncodeContext {
- int channels;
- int samplerate;
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];
- int32_t *predictor_buf;
+ int32_t sample_buf[MAX_CHANNELS][DEFAULT_FRAME_SIZE];
+ int32_t predictor_buf[DEFAULT_FRAME_SIZE];
int interlacing_shift;
int interlacing_leftweight;
PutBitContext pbctx;
@@ -69,37 +74,15 @@ typedef struct AlacEncodeContext {
} AlacEncodeContext;
-static void allocate_sample_buffers(AlacEncodeContext *s)
-{
- int i = s->channels;
-
- while(i) {
- s->sample_buf[i-1] = av_mallocz(s->avctx->frame_size*sizeof(int32_t));
- i--;
- }
- s->predictor_buf = av_mallocz(s->avctx->frame_size*sizeof(int32_t));
-}
-
-static void free_sample_buffers(AlacEncodeContext *s)
-{
- int i = s->channels;
-
- while(i) {
- av_freep(&s->sample_buf[i-1]);
- i--;
- }
- av_freep(&s->predictor_buf);
-}
-
static void init_sample_buffers(AlacEncodeContext *s, int16_t *input_samples)
{
int ch, i;
- for(ch=0;ch<s->channels;ch++) {
+ for(ch=0;ch<s->avctx->channels;ch++) {
int16_t *sptr = input_samples + ch;
for(i=0;i<s->avctx->frame_size;i++) {
s->sample_buf[ch][i] = *sptr;
- sptr += s->channels;
+ sptr += s->avctx->channels;
}
}
}
@@ -133,7 +116,7 @@ static void encode_scalar(AlacEncodeCont
static void write_frame_header(AlacEncodeContext *s, int is_verbatim)
{
- put_bits(&s->pbctx, 3, s->channels-1); // No. of channels -1
+ put_bits(&s->pbctx, 3, s->avctx->channels-1); // No. of channels -1
put_bits(&s->pbctx, 16, 0); // Seems to be zero
put_bits(&s->pbctx, 1, 1); // Sample count is in the header
put_bits(&s->pbctx, 2, 0); // FIXME: Wasted bytes field
@@ -147,7 +130,7 @@ static void calc_predictor_params(AlacEn
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,
+ opt_order = ff_lpc_calc_coefs(&s->dspctx, s->sample_buf[ch], s->avctx->frame_size, s->min_prediction_order, s->max_prediction_order,
ALAC_MAX_LPC_PRECISION, coefs, shift, 1, ORDER_METHOD_EST, ALAC_MAX_LPC_SHIFT, 1);
s->lpc[ch].lpc_order = opt_order;
@@ -155,19 +138,83 @@ static void calc_predictor_params(AlacEn
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;
+ int32_t lt, rt;
+ uint64_t sum[4];
+ uint64_t score[4];
+
+ /* calculate sum of 2nd order residual for each channel */
+ sum[0] = sum[1] = sum[2] = sum[3] = 0;
+ for(i=2; i<n; i++) {
+ lt = left_ch[i] - 2*left_ch[i-1] + left_ch[i-2];
+ rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2];
+ sum[2] += FFABS((lt + rt) >> 1);
+ sum[3] += FFABS(lt - rt);
+ sum[0] += FFABS(lt);
+ sum[1] += FFABS(rt);
+ }
+
+ /* calculate score for each mode */
+ score[0] = sum[0] + sum[1];
+ score[1] = sum[0] + sum[3];
+ score[2] = sum[1] + sum[3];
+ score[3] = sum[2] + sum[3];
+
+ /* return mode with lowest score */
+ best = 0;
+ for(i=1; i<4; i++) {
+ if(score[i] < score[best]) {
+ 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;
- int i;
- for(i=0; i<s->avctx->frame_size; i++) {
- tmp = left[i];
- left[i] = (tmp + right[i]) >> 1;
- right[i] = tmp - right[i];
+ 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;
}
- s->interlacing_leftweight = 1;
- s->interlacing_shift = 1;
}
static void alac_linear_predictor(AlacEncodeContext *s, int ch)
@@ -177,11 +224,10 @@ static void alac_linear_predictor(AlacEn
if(lpc.lpc_order == 31) {
s->predictor_buf[0] = s->sample_buf[ch][0];
- i = s->avctx->frame_size - 1;
- while(i > 0) {
+
+ for(i=1; i<s->avctx->frame_size; i++)
s->predictor_buf[i] = s->sample_buf[ch][i] - s->sample_buf[ch][i-1];
- i--;
- }
+
return;
}
@@ -192,12 +238,10 @@ static void alac_linear_predictor(AlacEn
int32_t *residual = s->predictor_buf;
// generate warm-up samples
- i = lpc.lpc_order;
residual[0] = samples[0];
- while(i > 0) {
+ for(i=1;i<=lpc.lpc_order;i++)
residual[i] = samples[i] - samples[i-1];
- i--;
- }
+
// perform lpc on remaining samples
for(i = lpc.lpc_order + 1; i < s->avctx->frame_size; i++) {
int sum = 0, res_val, j;
@@ -238,10 +282,10 @@ static void alac_linear_predictor(AlacEn
static void alac_entropy_coder(AlacEncodeContext *s)
{
unsigned int history = s->rc.initial_history;
- int sign_modifier = 0, i = 0, k;
+ int sign_modifier = 0, i, k;
int32_t *samples = s->predictor_buf;
- while(i < s->avctx->frame_size) {
+ for(i=0;i < s->avctx->frame_size;) {
int x;
k = av_log2((history >> 9) + 3);
@@ -291,7 +335,7 @@ static void write_compressed_frame(AlacE
put_bits(&s->pbctx, 8, s->interlacing_shift);
put_bits(&s->pbctx, 8, s->interlacing_leftweight);
- for(i=0;i<s->channels;i++) {
+ for(i=0;i<s->avctx->channels;i++) {
calc_predictor_params(s, i);
@@ -308,7 +352,7 @@ static void write_compressed_frame(AlacE
// apply lpc and entropy coding to audio samples
- for(i=0;i<s->channels;i++) {
+ for(i=0;i<s->avctx->channels;i++) {
alac_linear_predictor(s, i);
alac_entropy_coder(s);
}
@@ -321,8 +365,6 @@ static av_cold int alac_encode_init(AVCo
avctx->frame_size = DEFAULT_FRAME_SIZE;
avctx->bits_per_sample = DEFAULT_SAMPLE_SIZE;
- s->channels = avctx->channels;
- s->samplerate = avctx->sample_rate;
if(avctx->sample_fmt != SAMPLE_FMT_S16) {
av_log(avctx, AV_LOG_ERROR, "only pcm_s16 input samples are supported\n");
@@ -342,18 +384,18 @@ static av_cold int alac_encode_init(AVCo
s->rc.rice_modifier = 4;
s->max_coded_frame_size = (ALAC_FRAME_HEADER_SIZE + ALAC_FRAME_FOOTER_SIZE +
- avctx->frame_size*s->channels*avctx->bits_per_sample)>>3;
+ avctx->frame_size*avctx->channels*avctx->bits_per_sample)>>3;
- s->write_sample_size = avctx->bits_per_sample + s->channels - 1; // FIXME: consider wasted_bytes
+ s->write_sample_size = avctx->bits_per_sample + avctx->channels - 1; // FIXME: consider wasted_bytes
AV_WB32(alac_extradata, ALAC_EXTRADATA_SIZE);
AV_WB32(alac_extradata+4, MKBETAG('a','l','a','c'));
AV_WB32(alac_extradata+12, avctx->frame_size);
AV_WB8 (alac_extradata+17, avctx->bits_per_sample);
- AV_WB8 (alac_extradata+21, s->channels);
+ AV_WB8 (alac_extradata+21, avctx->channels);
AV_WB32(alac_extradata+24, s->max_coded_frame_size);
- AV_WB32(alac_extradata+28, s->samplerate*s->channels*avctx->bits_per_sample); // average bitrate
- AV_WB32(alac_extradata+32, s->samplerate);
+ AV_WB32(alac_extradata+28, avctx->sample_rate*avctx->channels*avctx->bits_per_sample); // average bitrate
+ AV_WB32(alac_extradata+32, avctx->sample_rate);
// Set relevant extradata fields
if(s->compression_level > 0) {
@@ -362,6 +404,36 @@ static av_cold int alac_encode_init(AVCo
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;
+ } else {
+ s->min_prediction_order = DEFAULT_MIN_PRED_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;
+ } else {
+ s->max_prediction_order = DEFAULT_MAX_PRED_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;
@@ -371,8 +443,6 @@ static av_cold int alac_encode_init(AVCo
s->avctx = avctx;
dsputil_init(&s->dspctx, avctx);
- allocate_sample_buffers(s);
-
return 0;
}
@@ -381,25 +451,26 @@ static int alac_encode_frame(AVCodecCont
{
AlacEncodeContext *s = avctx->priv_data;
PutBitContext *pb = &s->pbctx;
- int i, out_bytes;
+ int i, out_bytes, verbatim_flag = 0;
if(avctx->frame_size > DEFAULT_FRAME_SIZE) {
av_log(avctx, AV_LOG_ERROR, "input frame size exceeded\n");
return -1;
}
- if(buf_size < s->max_coded_frame_size) {
+ if(buf_size < 2*s->max_coded_frame_size) {
av_log(avctx, AV_LOG_ERROR, "buffer size is too small\n");
return -1;
}
+verbatim:
init_put_bits(pb, frame, buf_size);
- if(s->compression_level == 0) {
+ if((s->compression_level == 0) || verbatim_flag) {
// Verbatim mode
int16_t *samples = data;
write_frame_header(s, 1);
- for(i=0; i<avctx->frame_size*s->channels; i++) {
+ for(i=0; i<avctx->frame_size*avctx->channels; i++) {
put_sbits(pb, 16, *samples++);
}
} else {
@@ -414,22 +485,13 @@ static int alac_encode_frame(AVCodecCont
if(out_bytes > s->max_coded_frame_size) {
/* frame too large. use verbatim mode */
- int16_t *samples = data;
- init_put_bits(pb, frame, buf_size);
- write_frame_header(s, 0);
-
- for(i=0; i<avctx->frame_size*s->channels; i++) {
- put_sbits(pb, 16, *samples++);
- }
- put_bits(pb, 3, 7);
- flush_put_bits(pb);
- out_bytes = put_bits_count(pb) >> 3;
-
- if(out_bytes > s->max_coded_frame_size || out_bytes >= buf_size) {
+ if(verbatim_flag || (s->compression_level == 0)) {
/* still too large. must be an error. */
av_log(avctx, AV_LOG_ERROR, "error encoding frame\n");
return -1;
}
+ verbatim_flag = 1;
+ goto verbatim;
}
return out_bytes;
@@ -437,12 +499,9 @@ static int alac_encode_frame(AVCodecCont
static av_cold int alac_encode_close(AVCodecContext *avctx)
{
- AlacEncodeContext *s = avctx->priv_data;
-
av_freep(&avctx->extradata);
avctx->extradata_size = 0;
av_freep(&avctx->coded_frame);
- free_sample_buffers(s);
return 0;
}
@@ -455,5 +514,5 @@ AVCodec alac_encoder = {
alac_encode_frame,
alac_encode_close,
.capabilities = CODEC_CAP_SMALL_LAST_FRAME,
- .long_name = "ALAC (Apple Lossless Audio Codec)",
+ .long_name = NULL_IF_CONFIG_SMALL("ALAC (Apple Lossless Audio Codec)"),
};
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