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libavcodec
flvdec.c
Go to the documentation of this file.
1
/*
2
* FLV decoding.
3
* This file is part of FFmpeg.
4
*
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* FFmpeg is free software; you can redistribute it and/or
6
* modify it under the terms of the GNU Lesser General Public
7
* License as published by the Free Software Foundation; either
8
* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
11
* but WITHOUT ANY WARRANTY; without even the implied warranty of
12
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13
* Lesser General Public License for more details.
14
*
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* You should have received a copy of the GNU Lesser General Public
16
* License along with FFmpeg; if not, write to the Free Software
17
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "
mpegvideo.h
"
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#include "
h263.h
"
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#include "
flv.h
"
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#include "
libavutil/imgutils.h
"
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void
ff_flv2_decode_ac_esc
(
GetBitContext
*gb,
int
*
level
,
int
*
run
,
int
*last){
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int
is11 =
get_bits1
(gb);
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*last =
get_bits1
(gb);
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*run =
get_bits
(gb, 6);
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if
(is11){
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*level =
get_sbits
(gb, 11);
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}
else
{
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*level =
get_sbits
(gb, 7);
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}
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}
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int
ff_flv_decode_picture_header
(
MpegEncContext
*
s
)
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{
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int
format,
width
,
height
;
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/* picture header */
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if
(
get_bits_long
(&s->
gb
, 17) != 1) {
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av_log
(s->
avctx
,
AV_LOG_ERROR
,
"Bad picture start code\n"
);
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return
AVERROR_INVALIDDATA
;
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}
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format =
get_bits
(&s->
gb
, 5);
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if
(format != 0 && format != 1) {
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av_log
(s->
avctx
,
AV_LOG_ERROR
,
"Bad picture format\n"
);
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return
AVERROR_INVALIDDATA
;
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}
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s->
h263_flv
= format+1;
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s->
picture_number
=
get_bits
(&s->
gb
, 8);
/* picture timestamp */
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format =
get_bits
(&s->
gb
, 3);
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switch
(format) {
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case
0:
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width =
get_bits
(&s->
gb
, 8);
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height =
get_bits
(&s->
gb
, 8);
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break
;
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case
1:
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width =
get_bits
(&s->
gb
, 16);
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height =
get_bits
(&s->
gb
, 16);
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break
;
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case
2:
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width = 352;
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height = 288;
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break
;
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case
3:
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width = 176;
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height = 144;
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break
;
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case
4:
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width = 128;
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height = 96;
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break
;
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case
5:
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width = 320;
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height = 240;
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break
;
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case
6:
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width = 160;
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height = 120;
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break
;
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default
:
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width = height = 0;
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break
;
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}
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if
(
av_image_check_size
(width, height, 0, s->
avctx
))
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return
AVERROR
(EINVAL);
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s->
width
=
width
;
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s->
height
=
height
;
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s->
pict_type
=
AV_PICTURE_TYPE_I
+
get_bits
(&s->
gb
, 2);
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s->
droppable
= s->
pict_type
>
AV_PICTURE_TYPE_P
;
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if
(s->
droppable
)
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s->
pict_type
=
AV_PICTURE_TYPE_P
;
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skip_bits1
(&s->
gb
);
/* deblocking flag */
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s->
chroma_qscale
= s->
qscale
=
get_bits
(&s->
gb
, 5);
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s->
h263_plus
= 0;
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s->
unrestricted_mv
= 1;
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s->
h263_long_vectors
= 0;
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/* PEI */
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if
(
skip_1stop_8data_bits
(&s->
gb
) < 0)
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return
AVERROR_INVALIDDATA
;
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s->
f_code
= 1;
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if
(s->
ehc_mode
)
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s->
avctx
->
sample_aspect_ratio
= (
AVRational
){1,2};
111
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if
(s->
avctx
->
debug
&
FF_DEBUG_PICT_INFO
){
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av_log
(s->
avctx
,
AV_LOG_DEBUG
,
"%c esc_type:%d, qp:%d num:%d\n"
,
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s->
droppable
?
'D'
:
av_get_picture_type_char
(s->
pict_type
),
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s->
h263_flv
- 1, s->
qscale
, s->
picture_number
);
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}
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s->
y_dc_scale_table
=
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s->
c_dc_scale_table
=
ff_mpeg1_dc_scale_table
;
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return
0;
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}
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124
AVCodec
ff_flv_decoder
= {
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.
name
=
"flv"
,
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.long_name =
NULL_IF_CONFIG_SMALL
(
"FLV / Sorenson Spark / Sorenson H.263 (Flash Video)"
),
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.type =
AVMEDIA_TYPE_VIDEO
,
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.id =
AV_CODEC_ID_FLV1
,
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.priv_data_size =
sizeof
(
MpegEncContext
),
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.
init
=
ff_h263_decode_init
,
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.
close
=
ff_h263_decode_end
,
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.
decode
=
ff_h263_decode_frame
,
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.capabilities =
CODEC_CAP_DRAW_HORIZ_BAND
|
CODEC_CAP_DR1
,
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.max_lowres = 3,
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.pix_fmts =
ff_pixfmt_list_420
,
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};
Generated on Sun Mar 23 2014 23:49:54 for FFmpeg by
1.8.2