[FFmpeg-cvslog] avcodec/wavarc: add 5elp mode support
Paul B Mahol
git at videolan.org
Fri Jun 9 18:07:46 EEST 2023
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sun Feb 12 20:19:14 2023 +0100| [18b2ecc24778140c2bc798ed64842dc8feb6dc3a] | committer: Paul B Mahol
avcodec/wavarc: add 5elp mode support
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=18b2ecc24778140c2bc798ed64842dc8feb6dc3a
---
libavcodec/wavarc.c | 349 +++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 348 insertions(+), 1 deletion(-)
diff --git a/libavcodec/wavarc.c b/libavcodec/wavarc.c
index 7bfc276df4..6daad6a5a1 100644
--- a/libavcodec/wavarc.c
+++ b/libavcodec/wavarc.c
@@ -30,6 +30,8 @@
#include "unary.h"
typedef struct WavArcContext {
+ AVClass *av_class;
+
GetBitContext gb;
int shift;
@@ -47,6 +49,16 @@ typedef struct WavArcContext {
int pred[2][70];
int filter[2][70];
int samples[2][640];
+ uint8_t model[256];
+ uint16_t freqs[257];
+ uint16_t ac_value;
+ uint16_t ac_low;
+ uint16_t ac_high;
+ uint16_t range_high;
+ uint16_t range_low;
+ uint16_t freq_range;
+ int ac_pred[70];
+ int ac_out[570];
} WavArcContext;
static av_cold int wavarc_init(AVCodecContext *avctx)
@@ -90,6 +102,7 @@ static av_cold int wavarc_init(AVCodecContext *avctx)
case MKTAG('2','S','L','P'):
case MKTAG('3','N','L','P'):
case MKTAG('4','A','L','P'):
+ case MKTAG('5','E','L','P'):
s->nb_samples = 570;
s->offset = 70;
break;
@@ -343,7 +356,7 @@ static int decode_2slp(AVCodecContext *avctx,
break;
case 0:
order = get_urice(gb, 2);
- if ((unsigned)order >= FF_ARRAY_ELEMS(s->filter[ch]))
+ if ((unsigned)order > FF_ARRAY_ELEMS(s->filter[ch]))
return AVERROR_INVALIDDATA;
for (int o = 0; o < order; o++)
s->filter[ch][o] = get_srice(gb, 2);
@@ -378,6 +391,337 @@ static int decode_2slp(AVCodecContext *avctx,
return 0;
}
+static int ac_init(AVCodecContext *avctx,
+ WavArcContext *s, GetBitContext *gb)
+{
+ s->ac_low = 0;
+ s->ac_high = 0xffffu;
+ s->ac_value = get_bits(gb, 16);
+
+ s->freq_range = s->freqs[256];
+ if (!s->freq_range)
+ return AVERROR_INVALIDDATA;
+ return 0;
+}
+
+static unsigned ac_get_prob(WavArcContext *s)
+{
+ return ((s->freq_range - 1) + ((unsigned)s->ac_value - (unsigned)s->ac_low) *
+ (unsigned)s->freq_range) / (((unsigned)s->ac_high - (unsigned)s->ac_low) + 1) & 0xffffu;
+}
+
+static unsigned ac_map_symbol(WavArcContext *s, unsigned prob)
+{
+ int idx = 255;
+
+ while (prob < s->freqs[idx])
+ idx--;
+
+ s->range_high = s->freqs[idx + 1];
+ s->range_low = s->freqs[idx];
+
+ return idx;
+}
+
+static int ac_normalize(AVCodecContext *avctx, WavArcContext *s, GetBitContext *gb)
+{
+ int range;
+
+ range = (unsigned)s->ac_high - (unsigned)s->ac_low + 1;
+ s->ac_high = (int16_t)((range * (unsigned)s->range_high) / (unsigned)s->freq_range) + -1 + s->ac_low;
+ s->ac_low += (int16_t)((range * (unsigned)s->range_low) / (unsigned)s->freq_range);
+
+ for (;;) {
+ if ((s->ac_high & 0x8000) != (s->ac_low & 0x8000)) {
+ if ((s->ac_low & 0x4000) == 0 || (s->ac_high & 0x4000) != 0)
+ return 0;
+ s->ac_value ^= 0x4000;
+ s->ac_low &= 0x3fff;
+ s->ac_high |= 0x4000;
+ }
+
+ s->ac_low = s->ac_low << 1;
+ s->ac_high = s->ac_high * 2 + 1;
+ if (s->ac_high < s->ac_low) {
+ av_log(avctx, AV_LOG_ERROR, "invalid state\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ if (get_bits_left(gb) <= 0) {
+ av_log(avctx, AV_LOG_ERROR, "overread in arithmetic coder\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ s->ac_value = s->ac_value * 2 + get_bits1(gb);
+ }
+}
+
+static void ac_init_model(WavArcContext *s)
+{
+ memset(s->freqs, 0, sizeof(s->freqs));
+
+ for (int n = 0; n < 256; n++)
+ s->freqs[n+1] = s->model[n] + s->freqs[n];
+}
+
+static int ac_read_model(AVCodecContext *avctx,
+ WavArcContext *s,
+ GetBitContext *gb)
+{
+ unsigned start, end;
+
+ memset(s->model, 0, sizeof(s->model));
+
+ start = get_bits(gb, 8);
+ end = get_bits(gb, 8);
+
+ for (;;) {
+ while (start <= end)
+ s->model[start++] = get_bits(gb, 8);
+
+ if (get_bits_left(gb) < 8)
+ return AVERROR_INVALIDDATA;
+
+ if (get_bits_left(gb) < 8)
+ return AVERROR_INVALIDDATA;
+
+ start = get_bits(gb, 8);
+ if (!start)
+ break;
+
+ end = get_bits(gb, 8);
+ }
+
+ ac_init_model(s);
+
+ return 0;
+}
+
+static int decode_5elp(AVCodecContext *avctx,
+ WavArcContext *s, GetBitContext *gb)
+{
+ int ch, finished, fill, correlated, order = 0;
+
+ ch = 0;
+ finished = 0;
+ while (!finished) {
+ int *samples = s->samples[ch];
+ int *ac_pred = s->ac_pred;
+ int *ac_out = s->ac_out;
+ int k, block_type;
+
+ if (get_bits_left(gb) <= 0)
+ return AVERROR_INVALIDDATA;
+
+ memset(s->ac_out, 0, sizeof(s->ac_out));
+
+ block_type = get_urice(gb, 1);
+ av_log(avctx, AV_LOG_DEBUG, "block_type : %d\n", block_type);
+
+ if (block_type >= 0 && block_type <= 7) {
+ k = 1 + (avctx->sample_fmt == AV_SAMPLE_FMT_S16P);
+ k = get_urice(gb, k) + 1;
+ }
+
+ if (block_type <= 2 || block_type == 6 || block_type == 13 ||
+ block_type == 14 || block_type == 15 || block_type == 19) {
+ order = get_urice(gb, 2);
+ if ((unsigned)order > FF_ARRAY_ELEMS(s->filter[ch]))
+ return AVERROR_INVALIDDATA;
+ for (int o = 0; o < order; o++)
+ s->filter[ch][o] = get_srice(gb, 2);
+ }
+
+ if (block_type >= 0 && block_type <= 7) {
+ for (int n = 0; n < s->nb_samples; n++)
+ samples[n + 70] = get_srice(gb, k);
+ } else {
+ for (int n = 0; n < s->nb_samples; n++)
+ samples[n + 70] = 0;
+ }
+
+ if (block_type >= 13 && block_type <= 20) {
+ const int ac_size = get_bits(gb, 12);
+ const int ac_pos = get_bits_count(gb);
+ GetBitContext ac_gb = *gb;
+ int ret;
+
+ skip_bits_long(gb, ac_size);
+ ret = ac_read_model(avctx, s, &ac_gb);
+ if (ret < 0) {
+ av_log(avctx, AV_LOG_ERROR, "bad arithmetic model\n");
+ return ret;
+ }
+
+ ret = ac_init(avctx, s, &ac_gb);
+ if (ret < 0) {
+ av_log(avctx, AV_LOG_ERROR, "cannot init arithmetic decoder\n");
+ return ret;
+ }
+
+ for (int n = 0; n < s->nb_samples; n++) {
+ unsigned prob = ac_get_prob(s);
+ prob = ac_map_symbol(s, prob);
+ ac_out[n] = prob - 0x80;
+ if ((ret = ac_normalize(avctx, s, &ac_gb)) < 0)
+ return ret;
+ }
+
+ if (get_bits_count(&ac_gb) != ac_pos + ac_size) {
+ av_log(avctx, AV_LOG_DEBUG, "over/under-read in arithmetic coder: %d\n",
+ ac_pos + ac_size - get_bits_count(&ac_gb));
+ }
+ }
+
+ switch (block_type) {
+ case 12:
+ s->eof = 1;
+ return AVERROR_EOF;
+ case 11:
+ s->nb_samples = get_urice(gb, 8);
+ if (s->nb_samples > 570) {
+ s->nb_samples = 570;
+ return AVERROR_INVALIDDATA;
+ }
+ continue;
+ case 10:
+ s->shift = get_urice(gb, 2);
+ continue;
+ case 9:
+ if (avctx->sample_fmt == AV_SAMPLE_FMT_U8P) {
+ fill = (int8_t)get_bits(gb, 8);
+ fill -= 0x80;
+ } else {
+ fill = (int16_t)get_bits(gb, 16);
+ fill -= 0x8000;
+ }
+
+ for (int n = 0; n < s->nb_samples; n++)
+ samples[n + 70] = fill;
+ finished = 1;
+ break;
+ case 8:
+ for (int n = 0; n < s->nb_samples; n++)
+ samples[n + 70] = 0;
+ finished = 1;
+ break;
+ case 20:
+ case 7:
+ for (int n = 0; n < s->nb_samples; n++)
+ samples[n + 70] = ac_out[n] + samples[n + 69] * 3 - samples[n + 68] * 3 + samples[n + 67];
+ finished = 1;
+ break;
+ case 19:
+ case 6:
+ for (int n = 0; n < s->nb_samples; n++) {
+ int sum = 15;
+
+ for (int o = 0; o < order; o++)
+ sum += s->filter[ch][o] * (unsigned)samples[n + 70 - o - 1];
+
+ samples[n + 70] += ac_out[n] + (sum >> 4);
+ }
+ finished = 1;
+ break;
+ case 18:
+ case 5:
+ for (int n = 0; n < s->nb_samples; n++)
+ samples[n + 70] = ac_out[n] + samples[n + 69] * 2 - samples[n + 68];
+ finished = 1;
+ break;
+ case 17:
+ case 4:
+ for (int n = 0; n < s->nb_samples; n++)
+ samples[n + 70] = ac_out[n];
+ finished = 1;
+ break;
+ case 16:
+ case 3:
+ for (int n = 0; n < s->nb_samples; n++)
+ samples[n + 70] = ac_out[n] + samples[n + 69];
+ finished = 1;
+ break;
+ case 15:
+ case 2:
+ for (int n = 0; n < 70; n++) {
+ ac_pred[n] = samples[n];
+ samples[n] = 0;
+ }
+
+ for (int n = 0; n < s->nb_samples; n++) {
+ int sum = 15;
+
+ for (int o = 0; o < order; o++)
+ sum += s->filter[ch][o] * (unsigned)samples[n + 70 - o - 1];
+
+ samples[n + 70] += ac_out[n] + (sum >> 4);
+ }
+
+ for (int n = 0; n < 70; n++)
+ samples[n] = ac_pred[n];
+
+ for (int n = 0; n < s->nb_samples; n++)
+ samples[n + 70] += samples[n + 69] * 2 - samples[n + 68];
+
+ finished = 1;
+ break;
+ case 14:
+ case 1:
+ for (int n = 0; n < 70; n++) {
+ ac_pred[n] = samples[n];
+ samples[n] = 0;
+ }
+
+ for (int n = 0; n < s->nb_samples; n++) {
+ int sum = 15;
+
+ for (int o = 0; o < order; o++)
+ sum += s->filter[ch][o] * (unsigned)samples[n + 70 - o - 1];
+
+ samples[n + 70] += ac_out[n] + (sum >> 4);
+ }
+
+ for (int n = 0; n < 70; n++)
+ samples[n] = ac_pred[n];
+
+ for (int n = 0; n < s->nb_samples; n++)
+ samples[n + 70] += samples[n + 69];
+
+ finished = 1;
+ break;
+ case 13:
+ case 0:
+ for (int n = 0; n < s->nb_samples; n++) {
+ int sum = 15;
+
+ for (int o = 0; o < order; o++)
+ sum += s->filter[ch][o] * (unsigned)samples[n + 70 - o - 1];
+
+ samples[n + 70] += ac_out[n] + (sum >> 4);
+ }
+ finished = 1;
+ break;
+ default:
+ return AVERROR_INVALIDDATA;
+ }
+
+ if (finished == 1 && avctx->ch_layout.nb_channels == 2) {
+ if (ch == 0)
+ correlated = get_bits1(gb);
+ finished = ch != 0;
+ do_stereo(s, ch, correlated, 70);
+ ch = 1;
+ }
+ }
+
+ if (avctx->ch_layout.nb_channels == 1) {
+ for (int n = 0; n < 70; n++)
+ s->samples[0][n] = s->samples[0][s->nb_samples + n];
+ }
+
+ return 0;
+}
+
static int wavarc_decode(AVCodecContext *avctx, AVFrame *frame,
int *got_frame_ptr, AVPacket *pkt)
{
@@ -424,6 +768,9 @@ static int wavarc_decode(AVCodecContext *avctx, AVFrame *frame,
case MKTAG('4','A','L','P'):
ret = decode_2slp(avctx, s, gb);
break;
+ case MKTAG('5','E','L','P'):
+ ret = decode_5elp(avctx, s, gb);
+ break;
default:
ret = AVERROR_INVALIDDATA;
}
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