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alac: cosmetics: general pretty-printing and comment clean up

This commit is contained in:
Justin Ruggles 2012-07-09 17:02:42 -04:00
parent f3e5a7844b
commit eeb55f5f2f
1 changed files with 18 additions and 31 deletions
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43
libavcodec/alac.c
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@ -56,14 +56,11 @@
#define MAX_CHANNELS 8 #define MAX_CHANNELS 8
typedef struct { typedef struct {
AVCodecContext *avctx; AVCodecContext *avctx;
AVFrame frame; AVFrame frame;
GetBitContext gb; GetBitContext gb;
int channels; int channels;
/* buffers */
int32_t *predict_error_buffer[2]; int32_t *predict_error_buffer[2];
int32_t *output_samples_buffer[2]; int32_t *output_samples_buffer[2];
int32_t *extra_bits_buffer[2]; int32_t *extra_bits_buffer[2];
@ -145,16 +142,15 @@ static void rice_decompress(ALACContext *alac, int32_t *output_buffer,
int k; int k;
unsigned int x; unsigned int x;
/* read k, that is bits as is */ /* calculate rice param and decode next value */
k = av_log2((history >> 9) + 3); k = av_log2((history >> 9) + 3);
k = FFMIN(k, alac->rice_limit); k = FFMIN(k, alac->rice_limit);
x = decode_scalar(&alac->gb, k, bps); x = decode_scalar(&alac->gb, k, bps);
x += sign_modifier; x += sign_modifier;
sign_modifier = 0; sign_modifier = 0;
output_buffer[i] = (x >> 1) ^ -(x & 1); output_buffer[i] = (x >> 1) ^ -(x & 1);
/* now update the history */ /* update the history */
if (x > 0xffff) if (x > 0xffff)
history = 0xffff; history = 0xffff;
else else
@ -165,9 +161,9 @@ static void rice_decompress(ALACContext *alac, int32_t *output_buffer,
if ((history < 128) && (i + 1 < nb_samples)) { if ((history < 128) && (i + 1 < nb_samples)) {
int block_size; int block_size;
k = 7 - av_log2(history) + ((history + 16) >> 6 /* / 64 */); /* calculate rice param and decode block size */
k = 7 - av_log2(history) + ((history + 16) >> 6);
k = FFMIN(k, alac->rice_limit); k = FFMIN(k, alac->rice_limit);
block_size = decode_scalar(&alac->gb, k, 16); block_size = decode_scalar(&alac->gb, k, 16);
if (block_size > 0) { if (block_size > 0) {
@ -181,10 +177,8 @@ static void rice_decompress(ALACContext *alac, int32_t *output_buffer,
block_size * sizeof(*output_buffer)); block_size * sizeof(*output_buffer));
i += block_size; i += block_size;
} }
if (block_size <= 0xffff) if (block_size <= 0xffff)
sign_modifier = 1; sign_modifier = 1;
history = 0; history = 0;
} }
} }
@ -230,7 +224,6 @@ static void lpc_prediction(int32_t *error_buffer, int32_t *buffer_out,
/* NOTE: 4 and 8 are very common cases that could be optimized. */ /* NOTE: 4 and 8 are very common cases that could be optimized. */
/* general case */
for (i = lpc_order; i < nb_samples - 1; i++) { for (i = lpc_order; i < nb_samples - 1; i++) {
int j; int j;
int val = 0; int val = 0;
@ -238,13 +231,11 @@ static void lpc_prediction(int32_t *error_buffer, int32_t *buffer_out,
int error_sign; int error_sign;
int d = buffer_out[i - lpc_order]; int d = buffer_out[i - lpc_order];
for (j = 0; j < lpc_order; j++) { /* LPC prediction */
for (j = 0; j < lpc_order; j++)
val += (buffer_out[i - j] - d) * lpc_coefs[j]; val += (buffer_out[i - j] - d) * lpc_coefs[j];
}
val = (val + (1 << (lpc_quant - 1))) >> lpc_quant; val = (val + (1 << (lpc_quant - 1))) >> lpc_quant;
val += d + error_val; val += d + error_val;
buffer_out[i + 1] = sign_extend(val, bps); buffer_out[i + 1] = sign_extend(val, bps);
/* adapt LPC coefficients */ /* adapt LPC coefficients */
@ -262,9 +253,8 @@ static void lpc_prediction(int32_t *error_buffer, int32_t *buffer_out,
} }
} }
static void decorrelate_stereo(int32_t *buffer[2], static void decorrelate_stereo(int32_t *buffer[2], int nb_samples,
int nb_samples, int decorr_shift, int decorr_shift, int decorr_left_weight)
int decorr_left_weight)
{ {
int i; int i;
@ -282,8 +272,7 @@ static void decorrelate_stereo(int32_t *buffer[2],
} }
} }
static void append_extra_bits(int32_t *buffer[2], static void append_extra_bits(int32_t *buffer[2], int32_t *extra_bits_buffer[2],
int32_t *extra_bits_buffer[2],
int extra_bits, int channels, int nb_samples) int extra_bits, int channels, int nb_samples)
{ {
int i, ch; int i, ch;
@ -297,13 +286,9 @@ static int decode_element(AVCodecContext *avctx, void *data, int ch_index,
int channels) int channels)
{ {
ALACContext *alac = avctx->priv_data; ALACContext *alac = avctx->priv_data;
int has_size; int has_size, bps, is_compressed, decorr_shift, decorr_left_weight, ret;
int bps;
int is_compressed;
int decorr_shift;
int decorr_left_weight;
uint32_t output_samples; uint32_t output_samples;
int i, ch, ret; int i, ch;
skip_bits(&alac->gb, 4); /* element instance tag */ skip_bits(&alac->gb, 4); /* element instance tag */
skip_bits(&alac->gb, 12); /* unused header bits */ skip_bits(&alac->gb, 12); /* unused header bits */
@ -404,7 +389,8 @@ static int decode_element(AVCodecContext *avctx, void *data, int ch_index,
/* not compressed, easy case */ /* not compressed, easy case */
for (i = 0; i < alac->nb_samples; i++) { for (i = 0; i < alac->nb_samples; i++) {
for (ch = 0; ch < channels; ch++) { for (ch = 0; ch < channels; ch++) {
alac->output_samples_buffer[ch][i] = get_sbits_long(&alac->gb, alac->sample_size); alac->output_samples_buffer[ch][i] =
get_sbits_long(&alac->gb, alac->sample_size);
} }
} }
alac->extra_bits = 0; alac->extra_bits = 0;
@ -477,9 +463,10 @@ static int alac_decode_frame(AVCodecContext *avctx, void *data,
ch += channels; ch += channels;
} }
if (avpkt->size * 8 - get_bits_count(&alac->gb) > 8) if (avpkt->size * 8 - get_bits_count(&alac->gb) > 8) {
av_log(avctx, AV_LOG_ERROR, "Error : %d bits left\n", av_log(avctx, AV_LOG_ERROR, "Error : %d bits left\n",
avpkt->size * 8 - get_bits_count(&alac->gb)); avpkt->size * 8 - get_bits_count(&alac->gb));
}
*got_frame_ptr = 1; *got_frame_ptr = 1;
*(AVFrame *)data = alac->frame; *(AVFrame *)data = alac->frame;