[FFmpeg-devel] [PATCH 1/2] avcodec: add ADPCM IMA MTF decoder
Paul B Mahol
onemda at gmail.com
Sat Mar 14 13:56:00 EET 2020
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
libavcodec/Makefile | 1 +
libavcodec/adpcm.c | 33 +++++++++++++++++++++++++++++++++
libavcodec/allcodecs.c | 1 +
libavcodec/avcodec.h | 1 +
libavcodec/codec_desc.c | 7 +++++++
5 files changed, 43 insertions(+)
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index a3326a45e7..b50a26907f 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -843,6 +843,7 @@ OBJS-$(CONFIG_ADPCM_IMA_DK4_DECODER) += adpcm.o adpcm_data.o
OBJS-$(CONFIG_ADPCM_IMA_EA_EACS_DECODER) += adpcm.o adpcm_data.o
OBJS-$(CONFIG_ADPCM_IMA_EA_SEAD_DECODER) += adpcm.o adpcm_data.o
OBJS-$(CONFIG_ADPCM_IMA_ISS_DECODER) += adpcm.o adpcm_data.o
+OBJS-$(CONFIG_ADPCM_IMA_MTF_DECODER) += adpcm.o adpcm_data.o
OBJS-$(CONFIG_ADPCM_IMA_OKI_DECODER) += adpcm.o adpcm_data.o
OBJS-$(CONFIG_ADPCM_IMA_QT_DECODER) += adpcm.o adpcm_data.o
OBJS-$(CONFIG_ADPCM_IMA_QT_ENCODER) += adpcmenc.o adpcm_data.o
diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index 4f5980f7d5..e9abddc43c 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -89,6 +89,11 @@ static const int8_t zork_index_table[8] = {
-1, -1, -1, 1, 4, 7, 10, 12,
};
+static const int8_t mtf_index_table[16] = {
+ 8, 6, 4, 2, -1, -1, -1, -1,
+ -1, -1, -1, -1, 2, 4, 6, 8,
+};
+
/* end of tables */
typedef struct ADPCMDecodeContext {
@@ -304,6 +309,22 @@ static inline int16_t adpcm_ima_alp_expand_nibble(ADPCMChannelStatus *c, int8_t
return (int16_t)c->predictor;
}
+static inline int16_t adpcm_ima_mtf_expand_nibble(ADPCMChannelStatus *c, int nibble)
+{
+ int step_index, step, delta, predictor;
+
+ step = ff_adpcm_step_table[c->step_index];
+
+ delta = step * (2 * nibble - 15);
+ predictor = c->predictor + delta;
+
+ step_index = c->step_index + mtf_index_table[(unsigned)nibble];
+ c->predictor = av_clip_int16(predictor >> 4);
+ c->step_index = av_clip(step_index, 0, 88);
+
+ return (int16_t)c->predictor;
+}
+
static inline int16_t adpcm_ima_wav_expand_nibble(ADPCMChannelStatus *c, GetBitContext *gb, int bps)
{
int nibble, step_index, predictor, sign, delta, diff, step, shift;
@@ -700,6 +721,7 @@ static int get_nb_samples(AVCodecContext *avctx, GetByteContext *gb,
case AV_CODEC_ID_ADPCM_IMA_SSI:
case AV_CODEC_ID_ADPCM_IMA_APM:
case AV_CODEC_ID_ADPCM_IMA_ALP:
+ case AV_CODEC_ID_ADPCM_IMA_MTF:
nb_samples = buf_size * 2 / ch;
break;
}
@@ -1956,6 +1978,16 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
*samples++ = adpcm_zork_expand_nibble(&c->status[n % avctx->channels], v);
}
break;
+ case AV_CODEC_ID_ADPCM_IMA_MTF:
+ for (n = nb_samples / 2; n > 0; n--) {
+ for (channel = 0; channel < avctx->channels; channel++) {
+ int v = bytestream2_get_byteu(&gb);
+ *samples++ = adpcm_ima_mtf_expand_nibble(&c->status[channel], v >> 4);
+ samples[st] = adpcm_ima_mtf_expand_nibble(&c->status[channel], v & 0x0F);
+ }
+ samples += avctx->channels;
+ }
+ break;
default:
av_assert0(0); // unsupported codec_id should not happen
}
@@ -2027,6 +2059,7 @@ ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_DK4, sample_fmts_s16, adpcm_ima_dk4,
ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_EA_EACS, sample_fmts_s16, adpcm_ima_ea_eacs, "ADPCM IMA Electronic Arts EACS");
ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_EA_SEAD, sample_fmts_s16, adpcm_ima_ea_sead, "ADPCM IMA Electronic Arts SEAD");
ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_ISS, sample_fmts_s16, adpcm_ima_iss, "ADPCM IMA Funcom ISS");
+ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_MTF, sample_fmts_s16, adpcm_ima_mtf, "ADPCM IMA Capcom's MT Framework");
ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_OKI, sample_fmts_s16, adpcm_ima_oki, "ADPCM IMA Dialogic OKI");
ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_QT, sample_fmts_s16p, adpcm_ima_qt, "ADPCM IMA QuickTime");
ADPCM_DECODER(AV_CODEC_ID_ADPCM_IMA_RAD, sample_fmts_s16, adpcm_ima_rad, "ADPCM IMA Radical");
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index f4cf180716..379c5f7b81 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -608,6 +608,7 @@ extern AVCodec ff_adpcm_ima_dk4_decoder;
extern AVCodec ff_adpcm_ima_ea_eacs_decoder;
extern AVCodec ff_adpcm_ima_ea_sead_decoder;
extern AVCodec ff_adpcm_ima_iss_decoder;
+extern AVCodec ff_adpcm_ima_mtf_decoder;
extern AVCodec ff_adpcm_ima_oki_decoder;
extern AVCodec ff_adpcm_ima_qt_encoder;
extern AVCodec ff_adpcm_ima_qt_decoder;
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index aca3825fd3..9ac97a122b 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -553,6 +553,7 @@ enum AVCodecID {
AV_CODEC_ID_ADPCM_ZORK,
AV_CODEC_ID_ADPCM_IMA_APM,
AV_CODEC_ID_ADPCM_IMA_ALP,
+ AV_CODEC_ID_ADPCM_IMA_MTF,
/* AMR */
AV_CODEC_ID_AMR_NB = 0x12000,
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 0f5ddd9a9f..df3671765a 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -2332,6 +2332,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("ADPCM IMA High Voltage Software ALP"),
.props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY,
},
+ {
+ .id = AV_CODEC_ID_ADPCM_IMA_MTF,
+ .type = AVMEDIA_TYPE_AUDIO,
+ .name = "adpcm_ima_mtf",
+ .long_name = NULL_IF_CONFIG_SMALL("ADPCM IMA Capcom's MT Framework"),
+ .props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY,
+ },
/* AMR */
{
--
2.17.1
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