---
For Monkey's Audio 3.80-3.90 support an old entropy decoder should be added.
For even older versions both new filters and demuxer changes are needed
(because frames could start at any bit position back then).
---
libavcodec/apedec.c | 296 +++++++++++++++++++++++++++++++++++++++++++++++++--
libavformat/ape.c | 2 +-
2 files changed, 291 insertions(+), 7 deletions(-)
diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index 3597742..588bb4f 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -123,6 +123,8 @@ typedef struct APEPredictor {
int32_t coeffsA[2][4]; ///< adaption coefficients
int32_t coeffsB[2][5]; ///< adaption coefficients
int32_t historybuffer[HISTORY_SIZE + PREDICTOR_SIZE];
+
+ unsigned int sample_pos;
} APEPredictor;
/** Decoder context */
@@ -173,9 +175,12 @@ static void ape_apply_filters(APEContext *ctx, int32_t
*decoded0,
static void entropy_decode_mono_3900(APEContext *ctx, int blockstodecode);
static void entropy_decode_stereo_3900(APEContext *ctx, int blockstodecode);
+static void entropy_decode_stereo_3930(APEContext *ctx, int blockstodecode);
static void entropy_decode_mono_3990(APEContext *ctx, int blockstodecode);
static void entropy_decode_stereo_3990(APEContext *ctx, int blockstodecode);
+static void predictor_decode_mono_3800(APEContext *ctx, int count);
+static void predictor_decode_stereo_3800(APEContext *ctx, int count);
static void predictor_decode_mono_3930(APEContext *ctx, int count);
static void predictor_decode_stereo_3930(APEContext *ctx, int count);
static void predictor_decode_mono_3950(APEContext *ctx, int count);
@@ -235,7 +240,8 @@ static av_cold int ape_decode_init(AVCodecContext *avctx)
av_log(avctx, AV_LOG_DEBUG, "Compression Level: %d - Flags: %d\n",
s->compression_level, s->flags);
- if (s->compression_level % 1000 || s->compression_level >
COMPRESSION_LEVEL_INSANE) {
+ if (s->compression_level % 1000 || s->compression_level >
COMPRESSION_LEVEL_INSANE ||
+ (s->fileversion < 3930 && s->compression_level ==
COMPRESSION_LEVEL_INSANE)) {
av_log(avctx, AV_LOG_ERROR, "Incorrect compression level %d\n",
s->compression_level);
return AVERROR_INVALIDDATA;
@@ -249,15 +255,21 @@ static av_cold int ape_decode_init(AVCodecContext *avctx)
filter_alloc_fail);
}
- if (s->fileversion < 3990) {
+ if (s->fileversion < 3930) {
s->entropy_decode_mono = entropy_decode_mono_3900;
s->entropy_decode_stereo = entropy_decode_stereo_3900;
+ } else if (s->fileversion < 3990) {
+ s->entropy_decode_mono = entropy_decode_mono_3900;
+ s->entropy_decode_stereo = entropy_decode_stereo_3930;
} else {
s->entropy_decode_mono = entropy_decode_mono_3990;
s->entropy_decode_stereo = entropy_decode_stereo_3990;
}
- if (s->fileversion < 3950) {
+ if (s->fileversion < 3930) {
+ s->predictor_decode_mono = predictor_decode_mono_3800;
+ s->predictor_decode_stereo = predictor_decode_stereo_3800;
+ } else if (s->fileversion < 3950) {
s->predictor_decode_mono = predictor_decode_mono_3930;
s->predictor_decode_stereo = predictor_decode_stereo_3930;
} else {
@@ -526,6 +538,22 @@ static void entropy_decode_stereo_3900(APEContext *ctx,
int blockstodecode)
{
int32_t *decoded0 = ctx->decoded[0];
int32_t *decoded1 = ctx->decoded[1];
+ int blocks = blockstodecode;
+
+ while (blockstodecode--)
+ *decoded0++ = ape_decode_value_3900(ctx, &ctx->riceY);
+ range_dec_normalize(ctx);
+ // because of some implementation peculiarities we need to backpedal here
+ ctx->ptr -= 1;
+ range_start_decoding(ctx);
+ while (blocks--)
+ *decoded1++ = ape_decode_value_3900(ctx, &ctx->riceX);
+}
+
+static void entropy_decode_stereo_3930(APEContext *ctx, int blockstodecode)
+{
+ int32_t *decoded0 = ctx->decoded[0];
+ int32_t *decoded1 = ctx->decoded[1];
while (blockstodecode--) {
*decoded0++ = ape_decode_value_3900(ctx, &ctx->riceY);
@@ -583,7 +611,19 @@ static int init_entropy_decoder(APEContext *ctx)
return 0;
}
-static const int32_t initial_coeffs[4] = {
+static const int32_t initial_coeffs_fast_3320[1] = {
+ 375,
+};
+
+static const int32_t initial_coeffs_a_3800[3] = {
+ 64, 115, 64,
+};
+
+static const int32_t initial_coeffs_b_3800[2] = {
+ 740, 0
+};
+
+static const int32_t initial_coeffs_3930[4] = {
360, 317, -109, 98
};
@@ -596,13 +636,35 @@ static void init_predictor_decoder(APEContext *ctx)
p->buf = p->historybuffer;
/* Initialize and zero the coefficients */
- memcpy(p->coeffsA[0], initial_coeffs, sizeof(initial_coeffs));
- memcpy(p->coeffsA[1], initial_coeffs, sizeof(initial_coeffs));
+ if (ctx->fileversion < 3930) {
+ if (ctx->compression_level == COMPRESSION_LEVEL_FAST) {
+ memcpy(p->coeffsA[0], initial_coeffs_fast_3320,
+ sizeof(initial_coeffs_fast_3320));
+ memcpy(p->coeffsA[1], initial_coeffs_fast_3320,
+ sizeof(initial_coeffs_fast_3320));
+ } else {
+ memcpy(p->coeffsA[0], initial_coeffs_a_3800,
+ sizeof(initial_coeffs_a_3800));
+ memcpy(p->coeffsA[1], initial_coeffs_a_3800,
+ sizeof(initial_coeffs_a_3800));
+ }
+ } else {
+ memcpy(p->coeffsA[0], initial_coeffs_3930,
sizeof(initial_coeffs_3930));
+ memcpy(p->coeffsA[1], initial_coeffs_3930,
sizeof(initial_coeffs_3930));
+ }
memset(p->coeffsB, 0, sizeof(p->coeffsB));
+ if (ctx->fileversion < 3930) {
+ memcpy(p->coeffsB[0], initial_coeffs_b_3800,
+ sizeof(initial_coeffs_b_3800));
+ memcpy(p->coeffsB[1], initial_coeffs_b_3800,
+ sizeof(initial_coeffs_b_3800));
+ }
p->filterA[0] = p->filterA[1] = 0;
p->filterB[0] = p->filterB[1] = 0;
p->lastA[0] = p->lastA[1] = 0;
+
+ p->sample_pos = 0;
}
/** Get inverse sign of integer (-1 for positive, 1 for negative and 0 for
zero) */
@@ -610,6 +672,224 @@ static inline int APESIGN(int32_t x) {
return (x < 0) - (x > 0);
}
+static av_always_inline int filter_fast_3320(APEPredictor *p,
+ const int decoded, const int
filter,
+ const int delayA)
+{
+ int32_t predictionA;
+
+ p->buf[delayA] = p->lastA[filter];
+ if (p->sample_pos < 3) {
+ p->lastA[filter] = decoded;
+ p->filterA[filter] = decoded;
+ return decoded;
+ }
+
+ predictionA = p->buf[delayA] * 2 - p->buf[delayA - 1];
+ p->lastA[filter] = decoded + (predictionA * p->coeffsA[filter][0] >> 9);
+
+ if ((decoded ^ predictionA) > 0)
+ p->coeffsA[filter][0]++;
+ else
+ p->coeffsA[filter][0]--;
+
+ p->filterA[filter] += p->lastA[filter];
+
+ return p->filterA[filter];
+}
+
+static av_always_inline int filter_3800(APEPredictor *p,
+ const int decoded, const int filter,
+ const int delayA, const int delayB,
+ const int start, const int shift)
+{
+ int32_t predictionA, predictionB, sign;
+ int32_t d0, d1, d2, d3, d4;
+
+ p->buf[delayA] = p->lastA[filter];
+ p->buf[delayB] = p->filterB[filter];
+ if (p->sample_pos < start) {
+ predictionA = decoded + p->filterA[filter];
+ p->lastA[filter] = decoded;
+ p->filterB[filter] = decoded;
+ p->filterA[filter] = predictionA;
+ return predictionA;
+ }
+ d2 = p->buf[delayA];
+ d1 = (p->buf[delayA] - p->buf[delayA - 1]) << 1;
+ d0 = p->buf[delayA] + ((p->buf[delayA - 2] - p->buf[delayA - 1]) << 3);
+ d3 = p->buf[delayB] * 2 - p->buf[delayB - 1];
+ d4 = p->buf[delayB];
+
+ predictionA = d0 * p->coeffsA[filter][0] +
+ d1 * p->coeffsA[filter][1] +
+ d2 * p->coeffsA[filter][2];
+
+ sign = APESIGN(decoded);
+ p->coeffsA[filter][0] += (((d0 >> 30) & 2) - 1) * sign;
+ p->coeffsA[filter][1] += (((d1 >> 28) & 8) - 4) * sign;
+ p->coeffsA[filter][2] += (((d2 >> 28) & 8) - 4) * sign;
+
+ predictionB = d3 * p->coeffsB[filter][0] -
+ d4 * p->coeffsB[filter][1];
+ p->lastA[filter] = decoded + (predictionA >> 11);
+ sign = APESIGN(p->lastA[filter]);
+ p->coeffsB[filter][0] += (((d3 >> 29) & 4) - 2) * sign;
+ p->coeffsB[filter][1] -= (((d4 >> 30) & 2) - 1) * sign;
+
+ p->filterB[filter] = p->lastA[filter] + (predictionB >> shift);
+ p->filterA[filter] = p->filterB[filter] + ((p->filterA[filter] * 31) >> 5);
+
+ return p->filterA[filter];
+}
+
+static void long_filter_high_3800(int32_t *buffer, int order, int shift,
+ int32_t *coeffs, int32_t *delay, int length)
+{
+ int i, j;
+ int32_t dotprod, sign;
+
+ memset(coeffs, 0, order * sizeof(*coeffs));
+ for (i = 0; i < order; i++)
+ delay[i] = buffer[i];
+ for (i = order; i < length; i++) {
+ dotprod = 0;
+ sign = APESIGN(buffer[i]);
+ for (j = 0; j < order; j++) {
+ dotprod += delay[j] * coeffs[j];
+ coeffs[j] -= (((delay[j] >> 30) & 2) - 1) * sign;
+ }
+ buffer[i] -= dotprod >> shift;
+ for (j = 0; j < order - 1; j++)
+ delay[j] = delay[j + 1];
+ delay[order - 1] = buffer[i];
+ }
+}
+
+static void long_filter_ehigh_3830(int32_t *buffer, int length)
+{
+ int i, j;
+ int32_t dotprod, sign;
+ int32_t coeffs[8], delay[8];
+
+ memset(coeffs, 0, sizeof(coeffs));
+ memset(delay, 0, sizeof(delay));
+ for (i = 0; i < length; i++) {
+ dotprod = 0;
+ sign = APESIGN(buffer[i]);
+ for (j = 7; j >= 0; j--) {
+ dotprod += delay[j] * coeffs[j];
+ coeffs[j] -= (((delay[j] >> 30) & 2) - 1) * sign;
+ }
+ for (j = 7; j > 0; j--)
+ delay[j] = delay[j - 1];
+ delay[0] = buffer[i];
+ buffer[i] -= dotprod >> 9;
+ }
+}
+
+static void predictor_decode_stereo_3800(APEContext *ctx, int count)
+{
+ APEPredictor *p = &ctx->predictor;
+ int32_t *decoded0 = ctx->decoded[0];
+ int32_t *decoded1 = ctx->decoded[1];
+ int32_t coeffs[256], delay[256];
+ int start = 4, shift = 10;
+
+ if (ctx->compression_level == COMPRESSION_LEVEL_HIGH) {
+ start = 16;
+ long_filter_high_3800(decoded0, 16, 9, coeffs, delay, count);
+ long_filter_high_3800(decoded1, 16, 9, coeffs, delay, count);
+ } else if (ctx->compression_level == COMPRESSION_LEVEL_EXTRA_HIGH) {
+ int order = 128, shift2 = 11;
+
+ if (ctx->fileversion >= 3830) {
+ order <<= 1;
+ shift++;
+ shift2++;
+ long_filter_ehigh_3830(decoded0 + order, count - order);
+ long_filter_ehigh_3830(decoded1 + order, count - order);
+ }
+ start = order;
+ long_filter_high_3800(decoded0, order, shift2, coeffs, delay, count);
+ long_filter_high_3800(decoded1, order, shift2, coeffs, delay, count);
+ }
+
+ while (count--) {
+ int X = *decoded0, Y = *decoded1;
+ if (ctx->compression_level == COMPRESSION_LEVEL_FAST) {
+ *decoded0 = filter_fast_3320(p, Y, 0, YDELAYA);
+ decoded0++;
+ *decoded1 = filter_fast_3320(p, X, 1, XDELAYA);
+ decoded1++;
+ } else {
+ *decoded0 = filter_3800(p, Y, 0, YDELAYA, YDELAYB,
+ start, shift);
+ decoded0++;
+ *decoded1 = filter_3800(p, X, 1, XDELAYA, XDELAYB,
+ start, shift);
+ decoded1++;
+ }
+
+ /* Combined */
+ p->buf++;
+ p->sample_pos++;
+
+ /* Have we filled the history buffer? */
+ if (p->buf == p->historybuffer + HISTORY_SIZE) {
+ memmove(p->historybuffer, p->buf,
+ PREDICTOR_SIZE * sizeof(*p->historybuffer));
+ p->buf = p->historybuffer;
+ }
+ }
+}
+
+static void predictor_decode_mono_3800(APEContext *ctx, int count)
+{
+ APEPredictor *p = &ctx->predictor;
+ int32_t *decoded0 = ctx->decoded[0];
+ int32_t coeffs[256], delay[256];
+ int start = 4, shift = 10;
+
+ if (ctx->compression_level == COMPRESSION_LEVEL_HIGH) {
+ start = 16;
+ long_filter_high_3800(decoded0, 16, 9, coeffs, delay, count);
+ } else if (ctx->compression_level == COMPRESSION_LEVEL_EXTRA_HIGH) {
+ int order = 128, shift2 = 11;
+
+ if (ctx->fileversion >= 3830) {
+ order <<= 1;
+ shift++;
+ shift2++;
+ long_filter_ehigh_3830(decoded0 + order, count - order);
+ }
+ start = order;
+ long_filter_high_3800(decoded0, order, shift2, coeffs, delay, count);
+ }
+
+ while (count--) {
+ if (ctx->compression_level == COMPRESSION_LEVEL_FAST) {
+ *decoded0 = filter_fast_3320(p, *decoded0, 0, YDELAYA);
+ decoded0++;
+ } else {
+ *decoded0 = filter_3800(p, *decoded0, 0, YDELAYA, YDELAYB,
+ start, shift);
+ decoded0++;
+ }
+
+ /* Combined */
+ p->buf++;
+ p->sample_pos++;
+
+ /* Have we filled the history buffer? */
+ if (p->buf == p->historybuffer + HISTORY_SIZE) {
+ memmove(p->historybuffer, p->buf,
+ PREDICTOR_SIZE * sizeof(*p->historybuffer));
+ p->buf = p->historybuffer;
+ }
+ }
+}
+
static av_always_inline int predictor_update_3930(APEPredictor *p,
const int decoded, const int
filter,
const int delayA)
@@ -1048,6 +1328,10 @@ static int ape_decode_frame(AVCodecContext *avctx, void
*data,
}
blockstodecode = FFMIN(s->blocks_per_loop, s->samples);
+ // for old files stereo coefficients were not interleaved,
+ // so we need to decode all of them at once
+ if (s->fileversion < 3930 && s->channels == 2)
+ blockstodecode = s->samples;
/* reallocate decoded sample buffer if needed */
av_fast_malloc(&s->decoded_buffer, &s->decoded_size,
diff --git a/libavformat/ape.c b/libavformat/ape.c
index 7efc819..404dc41 100644
--- a/libavformat/ape.c
+++ b/libavformat/ape.c
@@ -28,7 +28,7 @@
#include "apetag.h"
/* The earliest and latest file formats supported by this library */
-#define APE_MIN_VERSION 3930
+#define APE_MIN_VERSION 3900
#define APE_MAX_VERSION 3990
#define MAC_FORMAT_FLAG_8_BIT 1 // is 8-bit [OBSOLETE]
--
1.7.9.5
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