wnv1.c
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1 /*
2  * Winnov WNV1 codec
3  * Copyright (c) 2005 Konstantin Shishkov
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
27 #include "avcodec.h"
28 #include "get_bits.h"
29 #include "libavutil/common.h"
30 
31 
32 typedef struct WNV1Context{
35 
36  int shift;
38 } WNV1Context;
39 
40 static const uint16_t code_tab[16][2]={
41 {0x1FD,9}, {0xFD,8}, {0x7D,7}, {0x3D,6}, {0x1D,5}, {0x0D,4}, {0x005,3},
42 {0x000,1},
43 {0x004,3}, {0x0C,4}, {0x1C,5}, {0x3C,6}, {0x7C,7}, {0xFC,8}, {0x1FC,9}, {0xFF,8}
44 };
45 
46 #define CODE_VLC_BITS 9
47 static VLC code_vlc;
48 
49 /* returns modified base_value */
50 static inline int wnv1_get_code(WNV1Context *w, int base_value)
51 {
52  int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1);
53 
54  if(v==15)
55  return av_reverse[ get_bits(&w->gb, 8 - w->shift) ];
56  else
57  return base_value + ((v - 7)<<w->shift);
58 }
59 
60 static int decode_frame(AVCodecContext *avctx,
61  void *data, int *data_size,
62  AVPacket *avpkt)
63 {
64  const uint8_t *buf = avpkt->data;
65  int buf_size = avpkt->size;
66  WNV1Context * const l = avctx->priv_data;
67  AVFrame * const p= (AVFrame*)&l->pic;
68  unsigned char *Y,*U,*V;
69  int i, j;
70  int prev_y = 0, prev_u = 0, prev_v = 0;
71  uint8_t *rbuf;
72 
73  if (buf_size < 8) {
74  av_log(avctx, AV_LOG_ERROR, "Packet is too short\n");
75  return AVERROR_INVALIDDATA;
76  }
77 
78  rbuf = av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
79  if(!rbuf){
80  av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n");
81  return -1;
82  }
83 
84  if(p->data[0])
85  avctx->release_buffer(avctx, p);
86 
87  p->reference = 0;
88  if(avctx->get_buffer(avctx, p) < 0){
89  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
90  av_free(rbuf);
91  return -1;
92  }
93  p->key_frame = 1;
94 
95  for(i=8; i<buf_size; i++)
96  rbuf[i]= av_reverse[ buf[i] ];
97  init_get_bits(&l->gb, rbuf+8, (buf_size-8)*8);
98 
99  if (buf[2] >> 4 == 6)
100  l->shift = 2;
101  else {
102  l->shift = 8 - (buf[2] >> 4);
103  if (l->shift > 4) {
104  av_log_ask_for_sample(avctx, "Unknown WNV1 frame header value %i\n",
105  buf[2] >> 4);
106  l->shift = 4;
107  }
108  if (l->shift < 1) {
109  av_log_ask_for_sample(avctx, "Unknown WNV1 frame header value %i\n",
110  buf[2] >> 4);
111  l->shift = 1;
112  }
113  }
114 
115  Y = p->data[0];
116  U = p->data[1];
117  V = p->data[2];
118  for (j = 0; j < avctx->height; j++) {
119  for (i = 0; i < avctx->width / 2; i++) {
120  Y[i * 2] = wnv1_get_code(l, prev_y);
121  prev_u = U[i] = wnv1_get_code(l, prev_u);
122  prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]);
123  prev_v = V[i] = wnv1_get_code(l, prev_v);
124  }
125  Y += p->linesize[0];
126  U += p->linesize[1];
127  V += p->linesize[2];
128  }
129 
130 
131  *data_size = sizeof(AVFrame);
132  *(AVFrame*)data = l->pic;
133  av_free(rbuf);
134 
135  return buf_size;
136 }
137 
138 static av_cold int decode_init(AVCodecContext *avctx){
139  WNV1Context * const l = avctx->priv_data;
140  static VLC_TYPE code_table[1 << CODE_VLC_BITS][2];
141 
142  l->avctx = avctx;
143  avctx->pix_fmt = PIX_FMT_YUV422P;
144 
145  code_vlc.table = code_table;
146  code_vlc.table_allocated = 1 << CODE_VLC_BITS;
147  init_vlc(&code_vlc, CODE_VLC_BITS, 16,
148  &code_tab[0][1], 4, 2,
149  &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
150 
151  return 0;
152 }
153 
154 static av_cold int decode_end(AVCodecContext *avctx){
155  WNV1Context * const l = avctx->priv_data;
156  AVFrame *pic = &l->pic;
157 
158  if (pic->data[0])
159  avctx->release_buffer(avctx, pic);
160 
161  return 0;
162 }
163 
165  .name = "wnv1",
166  .type = AVMEDIA_TYPE_VIDEO,
167  .id = CODEC_ID_WNV1,
168  .priv_data_size = sizeof(WNV1Context),
169  .init = decode_init,
170  .close = decode_end,
171  .decode = decode_frame,
172  .capabilities = CODEC_CAP_DR1,
173  .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
174 };
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:68
int(* get_buffer)(struct AVCodecContext *c, AVFrame *pic)
Called at the beginning of each frame to get a buffer for it.
Definition: avcodec.h:1726
const uint8_t av_reverse[256]
Definition: mathematics.c:52
GetBitContext gb
Definition: wnv1.c:37
enum PixelFormat pix_fmt
Pixel format, see PIX_FMT_xxx.
Definition: avcodec.h:1426
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
Audio Video Frame.
Definition: avcodec.h:985
void(* release_buffer)(struct AVCodecContext *c, AVFrame *pic)
Called to release buffers which were allocated with get_buffer.
Definition: avcodec.h:1737
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:237
static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
Definition: wnv1.c:60
int size
Definition: avcodec.h:909
AVCodec ff_wnv1_decoder
Definition: wnv1.c:164
#define VLC_TYPE
Definition: get_bits.h:61
AVCodec.
Definition: avcodec.h:3189
#define v(n)
Definition: regs.h:34
Definition: vf_drawbox.c:32
AVCodecContext * avctx
Definition: wnv1.c:33
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:228
#define av_cold
Definition: attributes.h:71
const char data[16]
Definition: mxf.c:60
uint8_t * data
Definition: avcodec.h:908
bitstream reader API header.
static av_cold int decode_end(AVCodecContext *avctx)
Definition: wnv1.c:154
#define V
Definition: options.c:69
static int init(AVCodecParserContext *s)
Definition: h264_parser.c:336
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:719
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:137
AVFrame pic
Definition: wnv1.c:34
int reference
is this picture used as reference The values for this are the same as the MpegEncContext.picture_structure variable, that is 1->top field, 2->bottom field, 3->frame/both fields.
Definition: avcodec.h:1074
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:191
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:140
const char * name
Name of the codec implementation.
Definition: avcodec.h:3196
Definition: get_bits.h:63
#define CODE_VLC_BITS
Definition: wnv1.c:46
static int wnv1_get_code(WNV1Context *w, int base_value)
Definition: wnv1.c:50
struct WNV1Context WNV1Context
int width
picture width / height.
Definition: avcodec.h:1408
struct AVFrame AVFrame
Audio Video Frame.
static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE(*table)[2], int bits, int max_depth)
Parse a vlc code.
Definition: get_bits.h:481
#define INIT_VLC_USE_NEW_STATIC
Definition: get_bits.h:399
int table_allocated
Definition: get_bits.h:66
int shift
Definition: wnv1.c:36
external API header
int linesize[AV_NUM_DATA_POINTERS]
Size, in bytes, of the data for each picture/channel plane.
Definition: avcodec.h:1008
void av_log_ask_for_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message asking for a sample.
main external API structure.
Definition: avcodec.h:1329
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:327
static VLC code_vlc
Definition: wnv1.c:47
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:111
#define init_vlc(vlc, nb_bits, nb_codes,bits, bits_wrap, bits_size,codes, codes_wrap, codes_size,flags)
Definition: get_bits.h:384
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:64
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:354
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:497
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: avcodec.h:997
common internal and external API header
static const uint16_t code_tab[16][2]
Definition: wnv1.c:40
void * priv_data
Definition: avcodec.h:1531
VLC_TYPE(* table)[2]
code, bits
Definition: get_bits.h:65
int key_frame
1 -> keyframe, 0-> not
Definition: avcodec.h:1022
Definition: vf_drawbox.c:32
static av_cold int decode_init(AVCodecContext *avctx)
Definition: wnv1.c:138