FFmpeg  4.3.6
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 #define BITSTREAM_READER_LE
28 #include "avcodec.h"
29 #include "get_bits.h"
30 #include "internal.h"
31 
32 
33 typedef struct WNV1Context {
34  int shift;
36 } WNV1Context;
37 
38 static const uint16_t code_tab[16][2] = {
39  { 0x17F, 9 }, { 0xBF, 8 }, { 0x5F, 7 }, { 0x2F, 6 }, { 0x17, 5 }, { 0x0B, 4 }, { 0x005, 3 },
40  { 0x000, 1 },
41  { 0x01, 3 }, { 0x03, 4 }, { 0x07, 5 }, { 0x0F, 6 }, { 0x1F, 7 }, { 0x3F, 8 }, { 0x07F, 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 get_bits(&w->gb, 8 - w->shift) << w->shift;
54  else
55  return base_value + ((v - 7U) << 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 
70  if (buf_size < 8 + avctx->height * (avctx->width/2)/8) {
71  av_log(avctx, AV_LOG_ERROR, "Packet size %d is too small\n", buf_size);
72  return AVERROR_INVALIDDATA;
73  }
74 
75  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
76  return ret;
77  p->key_frame = 1;
78 
79  if ((ret = init_get_bits8(&l->gb, buf + 8, buf_size - 8)) < 0)
80  return ret;
81 
82  if (buf[2] >> 4 == 6)
83  l->shift = 2;
84  else {
85  l->shift = 8 - (buf[2] >> 4);
86  if (l->shift > 4) {
88  "Unknown WNV1 frame header value %i",
89  buf[2] >> 4);
90  l->shift = 4;
91  }
92  if (l->shift < 1) {
94  "Unknown WNV1 frame header value %i",
95  buf[2] >> 4);
96  l->shift = 1;
97  }
98  }
99 
100  Y = p->data[0];
101  U = p->data[1];
102  V = p->data[2];
103  for (j = 0; j < avctx->height; j++) {
104  for (i = 0; i < avctx->width / 2; i++) {
105  Y[i * 2] = wnv1_get_code(l, prev_y);
106  prev_u = U[i] = wnv1_get_code(l, prev_u);
107  prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]);
108  prev_v = V[i] = wnv1_get_code(l, prev_v);
109  }
110  Y += p->linesize[0];
111  U += p->linesize[1];
112  V += p->linesize[2];
113  }
114 
115 
116  *got_frame = 1;
117 
118  return buf_size;
119 }
120 
122 {
123  static VLC_TYPE code_table[1 << CODE_VLC_BITS][2];
124 
125  if (avctx->width <= 1)
126  return AVERROR_INVALIDDATA;
127 
128  avctx->pix_fmt = AV_PIX_FMT_YUV422P;
129 
130  code_vlc.table = code_table;
131  code_vlc.table_allocated = 1 << CODE_VLC_BITS;
132  init_vlc(&code_vlc, CODE_VLC_BITS, 16,
133  &code_tab[0][1], 4, 2,
135 
136  return 0;
137 }
138 
140  .name = "wnv1",
141  .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
142  .type = AVMEDIA_TYPE_VIDEO,
143  .id = AV_CODEC_ID_WNV1,
144  .priv_data_size = sizeof(WNV1Context),
145  .init = decode_init,
146  .decode = decode_frame,
147  .capabilities = AV_CODEC_CAP_DR1,
148 };
GetBitContext gb
Definition: wnv1.c:35
#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:300
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
#define avpriv_request_sample(...)
int size
Definition: packet.h:356
AVCodec ff_wnv1_decoder
Definition: wnv1.c:139
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:736
#define init_vlc(vlc, nb_bits, nb_codes, bits, bits_wrap, bits_size, codes, codes_wrap, codes_size, flags)
Definition: vlc.h:38
AVCodec.
Definition: codec.h:190
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
uint8_t
#define av_cold
Definition: attributes.h:88
const char data[16]
Definition: mxf.c:91
#define height
uint8_t * data
Definition: packet.h:355
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 i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:188
const char * name
Name of the codec implementation.
Definition: codec.h:197
Definition: vlc.h:26
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:70
#define CODE_VLC_BITS
Definition: wnv1.c:44
static int wnv1_get_code(WNV1Context *w, int base_value)
Definition: wnv1.c:48
#define Y
Definition: boxblur.h:38
int width
picture width / height.
Definition: avcodec.h:699
uint8_t w
Definition: llviddspenc.c:38
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:797
#define INIT_VLC_LE
Definition: vlc.h:54
int table_allocated
Definition: vlc.h:29
int shift
Definition: wnv1.c:34
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:331
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:677
main external API structure.
Definition: avcodec.h:526
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: decode.c:1854
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:314
common internal api header.
static const uint16_t code_tab[16][2]
Definition: wnv1.c:38
#define INIT_VLC_USE_NEW_STATIC
Definition: vlc.h:55
void * priv_data
Definition: avcodec.h:553
VLC_TYPE(* table)[2]
code, bits
Definition: vlc.h:28
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:378
static av_cold int decode_init(AVCodecContext *avctx)
Definition: wnv1.c:121
#define VLC_TYPE
Definition: vlc.h:24
This structure stores compressed data.
Definition: packet.h:332
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:50
#define V
Definition: avdct.c:30