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体验新版 GitCode,发现更多精彩内容 >>
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e13894e8
编写于
8月 19, 2008
作者:
J
Jai Menon
浏览文件
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电子邮件补丁
差异文件
alacenc: last few hunks approved by michael
Originally committed as revision 14845 to
svn://svn.ffmpeg.org/ffmpeg/trunk
上级
cc940caf
变更
3
隐藏空白更改
内联
并排
Showing
3 changed file
with
112 addition
and
1 deletion
+112
-1
libavcodec/Makefile
libavcodec/Makefile
+1
-0
libavcodec/alacenc.c
libavcodec/alacenc.c
+110
-0
libavcodec/allcodecs.c
libavcodec/allcodecs.c
+1
-1
未找到文件。
libavcodec/Makefile
浏览文件 @
e13894e8
...
...
@@ -29,6 +29,7 @@ OBJS-$(CONFIG_AASC_DECODER) += aasc.o
OBJS-$(CONFIG_AC3_DECODER)
+=
ac3dec.o ac3tab.o ac3dec_data.o ac3.o mdct.o fft.o
OBJS-$(CONFIG_AC3_ENCODER)
+=
ac3enc.o ac3tab.o ac3.o
OBJS-$(CONFIG_ALAC_DECODER)
+=
alac.o
OBJS-$(CONFIG_ALAC_ENCODER)
+=
alacenc.o lpc.o
OBJS-$(CONFIG_AMV_DECODER)
+=
sp5xdec.o mjpegdec.o mjpeg.o
OBJS-$(CONFIG_APE_DECODER)
+=
apedec.o
OBJS-$(CONFIG_ASV1_DECODER)
+=
asv1.o mpeg12data.o
...
...
libavcodec/alacenc.c
浏览文件 @
e13894e8
...
...
@@ -217,6 +217,114 @@ static void alac_stereo_decorrelation(AlacEncodeContext *s)
}
}
static
void
alac_linear_predictor
(
AlacEncodeContext
*
s
,
int
ch
)
{
int
i
;
LPCContext
lpc
=
s
->
lpc
[
ch
];
if
(
lpc
.
lpc_order
==
31
)
{
s
->
predictor_buf
[
0
]
=
s
->
sample_buf
[
ch
][
0
];
for
(
i
=
1
;
i
<
s
->
avctx
->
frame_size
;
i
++
)
s
->
predictor_buf
[
i
]
=
s
->
sample_buf
[
ch
][
i
]
-
s
->
sample_buf
[
ch
][
i
-
1
];
return
;
}
// generalised linear predictor
if
(
lpc
.
lpc_order
>
0
)
{
int32_t
*
samples
=
s
->
sample_buf
[
ch
];
int32_t
*
residual
=
s
->
predictor_buf
;
// generate warm-up samples
residual
[
0
]
=
samples
[
0
];
for
(
i
=
1
;
i
<=
lpc
.
lpc_order
;
i
++
)
residual
[
i
]
=
samples
[
i
]
-
samples
[
i
-
1
];
// perform lpc on remaining samples
for
(
i
=
lpc
.
lpc_order
+
1
;
i
<
s
->
avctx
->
frame_size
;
i
++
)
{
int
sum
=
1
<<
(
lpc
.
lpc_quant
-
1
),
res_val
,
j
;
for
(
j
=
0
;
j
<
lpc
.
lpc_order
;
j
++
)
{
sum
+=
(
samples
[
lpc
.
lpc_order
-
j
]
-
samples
[
0
])
*
lpc
.
lpc_coeff
[
j
];
}
sum
>>=
lpc
.
lpc_quant
;
sum
+=
samples
[
0
];
residual
[
i
]
=
samples
[
lpc
.
lpc_order
+
1
]
-
sum
;
res_val
=
residual
[
i
];
if
(
res_val
)
{
int
index
=
lpc
.
lpc_order
-
1
;
int
neg
=
(
res_val
<
0
);
while
(
index
>=
0
&&
(
neg
?
(
res_val
<
0
)
:
(
res_val
>
0
)))
{
int
val
=
samples
[
0
]
-
samples
[
lpc
.
lpc_order
-
index
];
int
sign
=
(
val
?
FFSIGN
(
val
)
:
0
);
if
(
neg
)
sign
*=-
1
;
lpc
.
lpc_coeff
[
index
]
-=
sign
;
val
*=
sign
;
res_val
-=
((
val
>>
lpc
.
lpc_quant
)
*
(
lpc
.
lpc_order
-
index
));
index
--
;
}
}
samples
++
;
}
}
}
static
void
alac_entropy_coder
(
AlacEncodeContext
*
s
)
{
unsigned
int
history
=
s
->
rc
.
initial_history
;
int
sign_modifier
=
0
,
i
,
k
;
int32_t
*
samples
=
s
->
predictor_buf
;
for
(
i
=
0
;
i
<
s
->
avctx
->
frame_size
;)
{
int
x
;
k
=
av_log2
((
history
>>
9
)
+
3
);
x
=
-
2
*
(
*
samples
)
-
1
;
x
^=
(
x
>>
31
);
samples
++
;
i
++
;
encode_scalar
(
s
,
x
-
sign_modifier
,
k
,
s
->
write_sample_size
);
history
+=
x
*
s
->
rc
.
history_mult
-
((
history
*
s
->
rc
.
history_mult
)
>>
9
);
sign_modifier
=
0
;
if
(
x
>
0xFFFF
)
history
=
0xFFFF
;
if
((
history
<
128
)
&&
(
i
<
s
->
avctx
->
frame_size
))
{
unsigned
int
block_size
=
0
;
k
=
7
-
av_log2
(
history
)
+
((
history
+
16
)
>>
6
);
while
((
*
samples
==
0
)
&&
(
i
<
s
->
avctx
->
frame_size
))
{
samples
++
;
i
++
;
block_size
++
;
}
encode_scalar
(
s
,
block_size
,
k
,
16
);
sign_modifier
=
(
block_size
<=
0xFFFF
);
history
=
0
;
}
}
}
static
void
write_compressed_frame
(
AlacEncodeContext
*
s
)
{
int
i
,
j
;
...
...
@@ -295,6 +403,7 @@ static av_cold int alac_encode_init(AVCodecContext *avctx)
AV_WB8
(
alac_extradata
+
20
,
s
->
rc
.
k_modifier
);
}
s
->
min_prediction_order
=
DEFAULT_MIN_PRED_ORDER
;
if
(
avctx
->
min_prediction_order
>=
0
)
{
if
(
avctx
->
min_prediction_order
<
MIN_LPC_ORDER
||
avctx
->
min_prediction_order
>
MAX_LPC_ORDER
)
{
...
...
@@ -305,6 +414,7 @@ static av_cold int alac_encode_init(AVCodecContext *avctx)
s
->
min_prediction_order
=
avctx
->
min_prediction_order
;
}
s
->
max_prediction_order
=
DEFAULT_MAX_PRED_ORDER
;
if
(
avctx
->
max_prediction_order
>=
0
)
{
if
(
avctx
->
max_prediction_order
<
MIN_LPC_ORDER
||
avctx
->
max_prediction_order
>
MAX_LPC_ORDER
)
{
...
...
libavcodec/allcodecs.c
浏览文件 @
e13894e8
...
...
@@ -182,7 +182,7 @@ void avcodec_register_all(void)
/* audio codecs */
REGISTER_ENCDEC
(
AC3
,
ac3
);
REGISTER_
DECODER
(
ALAC
,
alac
);
REGISTER_
ENCDEC
(
ALAC
,
alac
);
REGISTER_DECODER
(
APE
,
ape
);
REGISTER_DECODER
(
ATRAC3
,
atrac3
);
REGISTER_DECODER
(
COOK
,
cook
);
...
...
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