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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 "avcodec.h"
28 #include "get_bits.h"
29 #include "internal.h"
30 #include "mathops.h"
31 
32 
33 typedef struct WNV1Context {
34  int shift;
36 } WNV1Context;
37 
38 static const uint16_t code_tab[16][2] = {
39  { 0x1FD, 9 }, { 0xFD, 8 }, { 0x7D, 7 }, { 0x3D, 6 }, { 0x1D, 5 }, { 0x0D, 4 }, { 0x005, 3 },
40  { 0x000, 1 },
41  { 0x004, 3 }, { 0x0C, 4 }, { 0x1C, 5 }, { 0x3C, 6 }, { 0x7C, 7 }, { 0xFC, 8 }, { 0x1FC, 9 }, { 0xFF, 8 }
42 };
43 
44 #define CODE_VLC_BITS 9
45 static VLC code_vlc;
46 
47 /* returns modified base_value */
48 static inline int wnv1_get_code(WNV1Context *w, int base_value)
49 {
50  int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1);
51 
52  if (v == 15)
53  return ff_reverse[get_bits(&w->gb, 8 - w->shift)];
54  else
55  return base_value + ((v - 7) << w->shift);
56 }
57 
58 static int decode_frame(AVCodecContext *avctx,
59  void *data, int *got_frame,
60  AVPacket *avpkt)
61 {
62  WNV1Context * const l = avctx->priv_data;
63  const uint8_t *buf = avpkt->data;
64  int buf_size = avpkt->size;
65  AVFrame * const p = data;
66  unsigned char *Y,*U,*V;
67  int i, j, ret;
68  int prev_y = 0, prev_u = 0, prev_v = 0;
69  uint8_t *rbuf;
70 
71  if (buf_size <= 8) {
72  av_log(avctx, AV_LOG_ERROR, "Packet size %d is too small\n", buf_size);
73  return AVERROR_INVALIDDATA;
74  }
75 
76  rbuf = av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
77  if (!rbuf) {
78  av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n");
79  return AVERROR(ENOMEM);
80  }
81  memset(rbuf + buf_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
82 
83  if ((ret = ff_get_buffer(avctx, p, 0)) < 0) {
84  av_free(rbuf);
85  return ret;
86  }
87  p->key_frame = 1;
88 
89  for (i = 8; i < buf_size; i++)
90  rbuf[i] = ff_reverse[buf[i]];
91 
92  if ((ret = init_get_bits8(&l->gb, rbuf + 8, buf_size - 8)) < 0)
93  return ret;
94 
95  if (buf[2] >> 4 == 6)
96  l->shift = 2;
97  else {
98  l->shift = 8 - (buf[2] >> 4);
99  if (l->shift > 4) {
100  avpriv_request_sample(avctx,
101  "Unknown WNV1 frame header value %i",
102  buf[2] >> 4);
103  l->shift = 4;
104  }
105  if (l->shift < 1) {
106  avpriv_request_sample(avctx,
107  "Unknown WNV1 frame header value %i",
108  buf[2] >> 4);
109  l->shift = 1;
110  }
111  }
112 
113  Y = p->data[0];
114  U = p->data[1];
115  V = p->data[2];
116  for (j = 0; j < avctx->height; j++) {
117  for (i = 0; i < avctx->width / 2; i++) {
118  Y[i * 2] = wnv1_get_code(l, prev_y);
119  prev_u = U[i] = wnv1_get_code(l, prev_u);
120  prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]);
121  prev_v = V[i] = wnv1_get_code(l, prev_v);
122  }
123  Y += p->linesize[0];
124  U += p->linesize[1];
125  V += p->linesize[2];
126  }
127 
128 
129  *got_frame = 1;
130  av_free(rbuf);
131 
132  return buf_size;
133 }
134 
136 {
137  static VLC_TYPE code_table[1 << CODE_VLC_BITS][2];
138 
139  avctx->pix_fmt = AV_PIX_FMT_YUV422P;
140 
141  code_vlc.table = code_table;
142  code_vlc.table_allocated = 1 << CODE_VLC_BITS;
143  init_vlc(&code_vlc, CODE_VLC_BITS, 16,
144  &code_tab[0][1], 4, 2,
145  &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
146 
147  return 0;
148 }
149 
151  .name = "wnv1",
152  .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
153  .type = AVMEDIA_TYPE_VIDEO,
154  .id = AV_CODEC_ID_WNV1,
155  .priv_data_size = sizeof(WNV1Context),
156  .init = decode_init,
157  .decode = decode_frame,
158  .capabilities = CODEC_CAP_DR1,
159 };
GetBitContext gb
Definition: wnv1.c:35
float v
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:171
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:260
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1174
AVCodec ff_wnv1_decoder
Definition: wnv1.c:150
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1471
#define VLC_TYPE
Definition: get_bits.h:61
AVCodec.
Definition: avcodec.h:3206
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
uint8_t
#define av_cold
Definition: attributes.h:74
#define av_malloc(s)
#define Y
Definition: vf_boxblur.c:76
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:794
uint8_t * data
Definition: avcodec.h:1173
bitstream reader API header.
#define av_log(a,...)
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: wnv1.c:58
#define U(x)
Definition: vp56_arith.h:37
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:175
const char * name
Name of the codec implementation.
Definition: avcodec.h:3213
Libavcodec external API header.
Definition: get_bits.h:63
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:67
#define CODE_VLC_BITS
Definition: wnv1.c:44
static int wnv1_get_code(WNV1Context *w, int base_value)
Definition: wnv1.c:48
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:635
ret
Definition: avfilter.c:974
int width
picture width / height.
Definition: avcodec.h:1430
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:555
#define INIT_VLC_USE_NEW_STATIC
Definition: get_bits.h:474
int table_allocated
Definition: get_bits.h:66
int shift
Definition: wnv1.c:34
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:199
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:441
main external API structure.
Definition: avcodec.h:1252
static VLC code_vlc
Definition: wnv1.c:45
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:1035
#define init_vlc(vlc, nb_bits, nb_codes,bits, bits_wrap, bits_size,codes, codes_wrap, codes_size,flags)
Definition: get_bits.h:457
void * buf
Definition: avisynth_c.h:553
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:182
static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)
Definition: ccaption_dec.c:522
common internal api header.
static const uint16_t code_tab[16][2]
Definition: wnv1.c:38
void * priv_data
Definition: avcodec.h:1294
#define av_free(p)
VLC_TYPE(* table)[2]
code, bits
Definition: get_bits.h:65
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:237
static av_cold int decode_init(AVCodecContext *avctx)
Definition: wnv1.c:135
const uint8_t ff_reverse[256]
Definition: mathtables.c:74
This structure stores compressed data.
Definition: avcodec.h:1150
#define V
Definition: avdct.c:30