intelh263dec.c
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1 /*
2  * H.263i decoder
3  *
4  * This file is part of Libav.
5  *
6  * Libav is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * Libav is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "mpegvideo.h"
22 #include "h263.h"
23 
24 /* don't understand why they choose a different header ! */
26 {
27  int format;
28 
29  /* picture header */
30  if (get_bits_long(&s->gb, 22) != 0x20) {
31  av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
32  return -1;
33  }
34  s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */
35 
36  if (get_bits1(&s->gb) != 1) {
37  av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n");
38  return -1; /* marker */
39  }
40  if (get_bits1(&s->gb) != 0) {
41  av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
42  return -1; /* h263 id */
43  }
44  skip_bits1(&s->gb); /* split screen off */
45  skip_bits1(&s->gb); /* camera off */
46  skip_bits1(&s->gb); /* freeze picture release off */
47 
48  format = get_bits(&s->gb, 3);
49  if (format == 0 || format == 6) {
50  av_log(s->avctx, AV_LOG_ERROR, "Intel H263 free format not supported\n");
51  return -1;
52  }
53  s->h263_plus = 0;
54 
56 
57  s->unrestricted_mv = get_bits1(&s->gb);
59 
60  if (get_bits1(&s->gb) != 0) {
61  av_log(s->avctx, AV_LOG_ERROR, "SAC not supported\n");
62  return -1; /* SAC: off */
63  }
64  s->obmc= get_bits1(&s->gb);
65  s->pb_frame = get_bits1(&s->gb);
66 
67  if (format < 6) {
68  s->width = ff_h263_format[format][0];
69  s->height = ff_h263_format[format][1];
70  s->avctx->sample_aspect_ratio.num = 12;
71  s->avctx->sample_aspect_ratio.den = 11;
72  } else {
73  format = get_bits(&s->gb, 3);
74  if(format == 0 || format == 7){
75  av_log(s->avctx, AV_LOG_ERROR, "Wrong Intel H263 format\n");
76  return -1;
77  }
78  if(get_bits(&s->gb, 2))
79  av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
80  s->loop_filter = get_bits1(&s->gb);
81  if(get_bits1(&s->gb))
82  av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
83  if(get_bits1(&s->gb))
84  s->pb_frame = 2;
85  if(get_bits(&s->gb, 5))
86  av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
87  if(get_bits(&s->gb, 5) != 1)
88  av_log(s->avctx, AV_LOG_ERROR, "Invalid marker\n");
89  }
90  if(format == 6){
91  int ar = get_bits(&s->gb, 4);
92  skip_bits(&s->gb, 9); // display width
93  skip_bits1(&s->gb);
94  skip_bits(&s->gb, 9); // display height
95  if(ar == 15){
96  s->avctx->sample_aspect_ratio.num = get_bits(&s->gb, 8); // aspect ratio - width
97  s->avctx->sample_aspect_ratio.den = get_bits(&s->gb, 8); // aspect ratio - height
98  } else {
100  }
101  if (s->avctx->sample_aspect_ratio.num == 0)
102  av_log(s->avctx, AV_LOG_ERROR, "Invalid aspect ratio.\n");
103  }
104 
105  s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
106  skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
107 
108  if(s->pb_frame){
109  skip_bits(&s->gb, 3); //temporal reference for B-frame
110  skip_bits(&s->gb, 2); //dbquant
111  }
112 
113  /* PEI */
114  while (get_bits1(&s->gb) != 0) {
115  skip_bits(&s->gb, 8);
116  }
117  s->f_code = 1;
118 
119  s->y_dc_scale_table=
121 
123 
124  return 0;
125 }
126 
128  .name = "h263i",
129  .type = AVMEDIA_TYPE_VIDEO,
130  .id = AV_CODEC_ID_H263I,
131  .priv_data_size = sizeof(MpegEncContext),
135  .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
136  .long_name = NULL_IF_CONFIG_SMALL("Intel H.263"),
137  .pix_fmts = ff_pixfmt_list_420,
138 };
int picture_number
Definition: mpegvideo.h:246
struct MpegEncContext MpegEncContext
MpegEncContext.
const uint8_t * y_dc_scale_table
qscale -> y_dc_scale table
Definition: mpegvideo.h:325
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:237
int num
numerator
Definition: rational.h:44
AVCodec ff_h263i_decoder
Definition: intelh263dec.c:127
int obmc
overlapped block motion compensation
Definition: mpegvideo.h:504
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown) That is the width of a pixel divided by the height of the pixel...
Definition: avcodec.h:1724
mpegvideo header.
const uint16_t ff_h263_format[8][2]
Definition: h263data.h:239
AVCodec.
Definition: avcodec.h:2960
int qscale
QP.
Definition: mpegvideo.h:343
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:228
enum AVPixelFormat ff_pixfmt_list_420[]
Definition: mpegvideo.c:128
const AVRational ff_h263_pixel_aspect[16]
Definition: h263data.h:280
static int init(AVCodecParserContext *s)
Definition: h264_parser.c:335
int h263_plus
h263 plus headers
Definition: mpegvideo.h:225
int unrestricted_mv
mv can point outside of the coded picture
Definition: mpegvideo.h:359
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:88
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:146
const char * name
Name of the codec implementation.
Definition: avcodec.h:2967
GetBitContext gb
Definition: mpegvideo.h:614
int ff_h263_decode_init(AVCodecContext *avctx)
Definition: h263dec.c:45
int ff_h263_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: h263dec.c:342
int pb_frame
PB frame mode (0 = none, 1 = base, 2 = improved)
Definition: mpegvideo.h:222
int ff_intel_h263_decode_picture_header(MpegEncContext *s)
Definition: intelh263dec.c:25
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:326
int height
picture size. must be a multiple of 16
Definition: mpegvideo.h:216
const uint8_t ff_mpeg1_dc_scale_table[128]
Definition: mpegvideo.c:73
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:268
static void skip_bits1(GetBitContext *s)
Definition: get_bits.h:293
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:260
int f_code
forward MV resolution
Definition: mpegvideo.h:364
static unsigned int get_bits_long(GetBitContext *s, int n)
Read 0-32 bits.
Definition: get_bits.h:301
int pict_type
AV_PICTURE_TYPE_I, AV_PICTURE_TYPE_P, AV_PICTURE_TYPE_B, ...
Definition: mpegvideo.h:350
const uint8_t * c_dc_scale_table
qscale -> c_dc_scale table
Definition: mpegvideo.h:326
MpegEncContext.
Definition: mpegvideo.h:212
struct AVCodecContext * avctx
Definition: mpegvideo.h:214
int den
denominator
Definition: rational.h:45
int ff_h263_decode_end(AVCodecContext *avctx)
Definition: h263dec.c:125
int chroma_qscale
chroma QP
Definition: mpegvideo.h:344
void ff_h263_show_pict_info(MpegEncContext *s)
Print picture info if FF_DEBUG_PICT_INFO is set.
Definition: ituh263dec.c:72
int h263_long_vectors
use horrible h263v1 long vector mode
Definition: mpegvideo.h:360