FFmpeg
wnv1.c
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1 /*
2  * Winnov WNV1 codec
3  * Copyright (c) 2005 Konstantin Shishkov
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Winnov WNV1 codec.
25  */
26 
27 #include "libavutil/thread.h"
28 
29 #define BITSTREAM_READER_LE
30 #include "avcodec.h"
31 #include "codec_internal.h"
32 #include "decode.h"
33 #include "get_bits.h"
34 
35 static const uint8_t code_tab[16][2] = {
36  { 7, 1 }, { 8, 3 }, { 6, 3 }, { 9, 4 }, { 5, 4 }, { 10, 5 }, { 4, 5 },
37  { 11, 6 }, { 3, 6 }, { 12, 7 }, { 2, 7 }, { 13, 8 }, { 1, 8 }, { 14, 9 },
38  { 0, 9 }, { 15, 8 }
39 };
40 
41 #define CODE_VLC_BITS 9
42 static VLC code_vlc;
43 
44 /* returns modified base_value */
45 static inline int wnv1_get_code(GetBitContext *gb, int shift, int base_value)
46 {
47  int v = get_vlc2(gb, code_vlc.table, CODE_VLC_BITS, 1);
48 
49  if (v == 8)
50  return get_bits(gb, 8 - shift) << shift;
51  else
52  return base_value + v * (1 << shift);
53 }
54 
55 static int decode_frame(AVCodecContext *avctx, AVFrame *p,
56  int *got_frame, AVPacket *avpkt)
57 {
58  const uint8_t *buf = avpkt->data;
59  int buf_size = avpkt->size;
60  GetBitContext gb;
61  unsigned char *Y,*U,*V;
62  int i, j, ret, shift;
63  int prev_y = 0, prev_u = 0, prev_v = 0;
64 
65  if (buf_size < 8 + avctx->height * (avctx->width/2)/8) {
66  av_log(avctx, AV_LOG_ERROR, "Packet size %d is too small\n", buf_size);
67  return AVERROR_INVALIDDATA;
68  }
69 
70  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
71  return ret;
72  p->key_frame = 1;
73 
74  if ((ret = init_get_bits8(&gb, buf + 8, buf_size - 8)) < 0)
75  return ret;
76 
77  if (buf[2] >> 4 == 6)
78  shift = 2;
79  else {
80  shift = 8 - (buf[2] >> 4);
81  if (shift > 4) {
83  "Unknown WNV1 frame header value %i",
84  buf[2] >> 4);
85  shift = 4;
86  }
87  if (shift < 1) {
89  "Unknown WNV1 frame header value %i",
90  buf[2] >> 4);
91  shift = 1;
92  }
93  }
94 
95  Y = p->data[0];
96  U = p->data[1];
97  V = p->data[2];
98  for (j = 0; j < avctx->height; j++) {
99  for (i = 0; i < avctx->width / 2; i++) {
100  Y[i * 2] = wnv1_get_code(&gb, shift, prev_y);
101  prev_u = U[i] = wnv1_get_code(&gb, shift, prev_u);
102  prev_y = Y[(i * 2) + 1] = wnv1_get_code(&gb, shift, Y[i * 2]);
103  prev_v = V[i] = wnv1_get_code(&gb, shift, prev_v);
104  }
105  Y += p->linesize[0];
106  U += p->linesize[1];
107  V += p->linesize[2];
108  }
109 
110 
111  *got_frame = 1;
112 
113  return buf_size;
114 }
115 
116 static av_cold void wnv1_init_static(void)
117 {
119  &code_tab[0][1], 2,
120  &code_tab[0][0], 2, 1,
122 }
123 
125 {
126  static AVOnce init_static_once = AV_ONCE_INIT;
127 
128  if (avctx->width <= 1)
129  return AVERROR_INVALIDDATA;
130 
131  avctx->pix_fmt = AV_PIX_FMT_YUV422P;
132 
133  ff_thread_once(&init_static_once, wnv1_init_static);
134 
135  return 0;
136 }
137 
139  .p.name = "wnv1",
140  CODEC_LONG_NAME("Winnov WNV1"),
141  .p.type = AVMEDIA_TYPE_VIDEO,
142  .p.id = AV_CODEC_ID_WNV1,
143  .init = decode_init,
145  .p.capabilities = AV_CODEC_CAP_DR1,
146 };
code_vlc
static VLC code_vlc
Definition: wnv1.c:42
INIT_VLC_OUTPUT_LE
#define INIT_VLC_OUTPUT_LE
Definition: vlc.h:98
thread.h
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AV_CODEC_ID_WNV1
@ AV_CODEC_ID_WNV1
Definition: codec_id.h:125
AVPacket::data
uint8_t * data
Definition: packet.h:374
FFCodec
Definition: codec_internal.h:119
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:346
CODE_VLC_BITS
#define CODE_VLC_BITS
Definition: wnv1.c:41
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:123
GetBitContext
Definition: get_bits.h:61
AVFrame::key_frame
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:417
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: wnv1.c:124
ff_thread_once
static int ff_thread_once(char *control, void(*routine)(void))
Definition: thread.h:184
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:667
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:298
decode.h
get_bits.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:264
AV_ONCE_INIT
#define AV_ONCE_INIT
Definition: thread.h:182
INIT_VLC_STATIC_FROM_LENGTHS
#define INIT_VLC_STATIC_FROM_LENGTHS(vlc, bits, nb_codes, lens, len_wrap, symbols, symbols_wrap, symbols_size, offset, flags, static_size)
Definition: vlc.h:131
V
#define V
Definition: avdct.c:30
get_vlc2
static av_always_inline int get_vlc2(GetBitContext *s, const VLCElem *table, int bits, int max_depth)
Parse a vlc code.
Definition: get_bits.h:787
AVOnce
#define AVOnce
Definition: thread.h:181
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1450
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:375
codec_internal.h
ff_wnv1_decoder
const FFCodec ff_wnv1_decoder
Definition: wnv1.c:138
shift
static int shift(int a, int b)
Definition: bonk.c:253
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *p, int *got_frame, AVPacket *avpkt)
Definition: wnv1.c:55
height
#define height
code_tab
static const uint8_t code_tab[16][2]
Definition: wnv1.c:35
Y
#define Y
Definition: boxblur.h:37
wnv1_init_static
static av_cold void wnv1_init_static(void)
Definition: wnv1.c:116
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
AVCodecContext::height
int height
Definition: avcodec.h:571
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
avcodec.h
ret
ret
Definition: filter_design.txt:187
wnv1_get_code
static int wnv1_get_code(GetBitContext *gb, int shift, int base_value)
Definition: wnv1.c:45
U
#define U(x)
Definition: vpx_arith.h:37
AVCodecContext
main external API structure.
Definition: avcodec.h:398
VLC
Definition: vlc.h:31
VLC::table
VLCElem * table
Definition: vlc.h:33
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AV_PIX_FMT_YUV422P
@ AV_PIX_FMT_YUV422P
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:70
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:36
AVPacket
This structure stores compressed data.
Definition: packet.h:351
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:571
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:370
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61