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avcodec: add Gremlin DPCM decoder

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Signed-off-by: Paul B Mahol <onemda@gmail.com>
This commit is contained in:
Paul B Mahol 2017-06-02 12:43:02 +02:00
parent 22a25ab389
commit 29bdcf588f
6 changed files with 50 additions and 8 deletions
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1
libavcodec/Makefile
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@ -310,6 +310,7 @@ OBJS-$(CONFIG_G723_1_ENCODER) += g723_1enc.o g723_1.o \
OBJS-$(CONFIG_G729_DECODER) += g729dec.o lsp.o celp_math.o celp_filters.o acelp_filters.o acelp_pitch_delay.o acelp_vectors.o g729postfilter.o
OBJS-$(CONFIG_GIF_DECODER) += gifdec.o lzw.o
OBJS-$(CONFIG_GIF_ENCODER) += gif.o lzwenc.o
OBJS-$(CONFIG_GREMLIN_DPCM_DECODER) += dpcm.o
OBJS-$(CONFIG_GSM_DECODER) += gsmdec.o gsmdec_data.o msgsmdec.o
OBJS-$(CONFIG_GSM_MS_DECODER) += gsmdec.o gsmdec_data.o msgsmdec.o
OBJS-$(CONFIG_H261_DECODER) += h261dec.o h261data.o h261.o

1
libavcodec/allcodecs.c
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@ -520,6 +520,7 @@ static void register_all(void)
REGISTER_DECODER(PCM_ZORK, pcm_zork);
/* DPCM codecs */
REGISTER_DECODER(GREMLIN_DPCM, gremlin_dpcm);
REGISTER_DECODER(INTERPLAY_DPCM, interplay_dpcm);
REGISTER_ENCDEC (ROQ_DPCM, roq_dpcm);
REGISTER_DECODER(SOL_DPCM, sol_dpcm);

1
libavcodec/avcodec.h
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@ -548,6 +548,7 @@ enum AVCodecID {
AV_CODEC_ID_SOL_DPCM,
AV_CODEC_ID_SDX2_DPCM = 0x14800,
AV_CODEC_ID_GREMLIN_DPCM,
/* audio codecs */
AV_CODEC_ID_MP2 = 0x15000,

7
libavcodec/codec_desc.c
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@ -2249,6 +2249,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("DPCM Squareroot-Delta-Exact"),
.props = AV_CODEC_PROP_LOSSY,
},
{
.id = AV_CODEC_ID_GREMLIN_DPCM,
.type = AVMEDIA_TYPE_AUDIO,
.name = "gremlin_dpcm",
.long_name = NULL_IF_CONFIG_SMALL("DPCM Gremlin"),
.props = AV_CODEC_PROP_LOSSY,
},
/* audio codecs */
{

44
libavcodec/dpcm.c
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@ -44,7 +44,7 @@
#include "mathops.h"
typedef struct DPCMContext {
int16_t square_array[256];
int16_t array[256];
int sample[2]; ///< previous sample (for SOL_DPCM)
const int8_t *sol_table; ///< delta table for SOL_DPCM
} DPCMContext;
@ -130,8 +130,8 @@ static av_cold int dpcm_decode_init(AVCodecContext *avctx)
/* initialize square table */
for (i = 0; i < 128; i++) {
int16_t square = i * i;
s->square_array[i ] = square;
s->square_array[i + 128] = -square;
s->array[i ] = square;
s->array[i + 128] = -square;
}
break;
@ -156,7 +156,25 @@ static av_cold int dpcm_decode_init(AVCodecContext *avctx)
case AV_CODEC_ID_SDX2_DPCM:
for (i = -128; i < 128; i++) {
int16_t square = i * i * 2;
s->square_array[i+128] = i < 0 ? -square: square;
s->array[i+128] = i < 0 ? -square: square;
}
break;
case AV_CODEC_ID_GREMLIN_DPCM: {
int delta = 0;
int code = 64;
int step = 45;
s->array[0] = 0;
for (i = 0; i < 127; i++) {
delta += (code >> 5);
code += step;
step += 2;
s->array[i*2 + 1] = delta;
s->array[i*2 + 2] = -delta;
}
s->array[255] = delta + (code >> 5);
}
break;
@ -207,6 +225,7 @@ static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
else
out = buf_size;
break;
case AV_CODEC_ID_GREMLIN_DPCM:
case AV_CODEC_ID_SDX2_DPCM:
out = buf_size;
break;
@ -240,7 +259,7 @@ static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
/* decode the samples */
while (output_samples < samples_end) {
predictor[ch] += s->square_array[bytestream2_get_byteu(&gb)];
predictor[ch] += s->array[bytestream2_get_byteu(&gb)];
predictor[ch] = av_clip_int16(predictor[ch]);
*output_samples++ = predictor[ch];
@ -335,12 +354,24 @@ static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
if (!(n & 1))
s->sample[ch] = 0;
s->sample[ch] += s->square_array[n + 128];
s->sample[ch] += s->array[n + 128];
s->sample[ch] = av_clip_int16(s->sample[ch]);
*output_samples++ = s->sample[ch];
ch ^= stereo;
}
break;
case AV_CODEC_ID_GREMLIN_DPCM: {
int idx = 0;
while (output_samples < samples_end) {
uint8_t n = bytestream2_get_byteu(&gb);
*output_samples++ = s->sample[idx] += s->array[n];
idx ^= 1;
}
}
break;
}
*got_frame_ptr = 1;
@ -360,6 +391,7 @@ AVCodec ff_ ## name_ ## _decoder = { \
.capabilities = AV_CODEC_CAP_DR1, \
}
DPCM_DECODER(AV_CODEC_ID_GREMLIN_DPCM, gremlin_dpcm, "DPCM Gremlin");
DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
DPCM_DECODER(AV_CODEC_ID_SDX2_DPCM, sdx2_dpcm, "DPCM Squareroot-Delta-Exact");

4
libavcodec/version.h
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@ -28,8 +28,8 @@
#include "libavutil/version.h"
#define LIBAVCODEC_VERSION_MAJOR 57
#define LIBAVCODEC_VERSION_MINOR 96
#define LIBAVCODEC_VERSION_MICRO 101
#define LIBAVCODEC_VERSION_MINOR 97
#define LIBAVCODEC_VERSION_MICRO 100
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
LIBAVCODEC_VERSION_MINOR, \