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 "internal.h"
30 #include "mathops.h"
31 
32 
33 typedef struct WNV1Context {
36 
37  int shift;
39 } WNV1Context;
40 
41 static const uint16_t code_tab[16][2] = {
42  { 0x1FD, 9 }, { 0xFD, 8 }, { 0x7D, 7 }, { 0x3D, 6 }, { 0x1D, 5 }, { 0x0D, 4 }, { 0x005, 3 },
43  { 0x000, 1 },
44  { 0x004, 3 }, { 0x0C, 4 }, { 0x1C, 5 }, { 0x3C, 6 }, { 0x7C, 7 }, { 0xFC, 8 }, { 0x1FC, 9 }, { 0xFF, 8 }
45 };
46 
47 #define CODE_VLC_BITS 9
48 static VLC code_vlc;
49 
50 /* returns modified base_value */
51 static inline int wnv1_get_code(WNV1Context *w, int base_value)
52 {
53  int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1);
54 
55  if (v == 15)
56  return ff_reverse[get_bits(&w->gb, 8 - w->shift)];
57  else
58  return base_value + ((v - 7) << w->shift);
59 }
60 
61 static int decode_frame(AVCodecContext *avctx,
62  void *data, int *got_frame,
63  AVPacket *avpkt)
64 {
65  WNV1Context * const l = avctx->priv_data;
66  const uint8_t *buf = avpkt->data;
67  int buf_size = avpkt->size;
68  AVFrame * const p = &l->pic;
69  unsigned char *Y,*U,*V;
70  int i, j;
71  int prev_y = 0, prev_u = 0, prev_v = 0;
72  uint8_t *rbuf;
73 
74  if (buf_size < 8) {
75  av_log(avctx, AV_LOG_ERROR, "Packet is too short\n");
76  return AVERROR_INVALIDDATA;
77  }
78 
79  rbuf = av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
80  if (!rbuf) {
81  av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n");
82  return -1;
83  }
84 
85  if (p->data[0])
86  avctx->release_buffer(avctx, p);
87 
88  p->reference = 0;
89  if(ff_get_buffer(avctx, p) < 0){
90  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
91  av_free(rbuf);
92  return -1;
93  }
94  p->key_frame = 1;
95 
96  for (i = 8; i < buf_size; i++)
97  rbuf[i] = ff_reverse[buf[i]];
98  init_get_bits(&l->gb, rbuf + 8, (buf_size - 8) * 8);
99 
100  if (buf[2] >> 4 == 6)
101  l->shift = 2;
102  else {
103  l->shift = 8 - (buf[2] >> 4);
104  if (l->shift > 4) {
105  av_log_ask_for_sample(avctx, "Unknown WNV1 frame header value %i\n",
106  buf[2] >> 4);
107  l->shift = 4;
108  }
109  if (l->shift < 1) {
110  av_log_ask_for_sample(avctx, "Unknown WNV1 frame header value %i\n",
111  buf[2] >> 4);
112  l->shift = 1;
113  }
114  }
115 
116  Y = p->data[0];
117  U = p->data[1];
118  V = p->data[2];
119  for (j = 0; j < avctx->height; j++) {
120  for (i = 0; i < avctx->width / 2; i++) {
121  Y[i * 2] = wnv1_get_code(l, prev_y);
122  prev_u = U[i] = wnv1_get_code(l, prev_u);
123  prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]);
124  prev_v = V[i] = wnv1_get_code(l, prev_v);
125  }
126  Y += p->linesize[0];
127  U += p->linesize[1];
128  V += p->linesize[2];
129  }
130 
131 
132  *got_frame = 1;
133  *(AVFrame*)data = l->pic;
134  av_free(rbuf);
135 
136  return buf_size;
137 }
138 
140 {
141  WNV1Context * const l = avctx->priv_data;
142  static VLC_TYPE code_table[1 << CODE_VLC_BITS][2];
143 
144  l->avctx = avctx;
145  avctx->pix_fmt = AV_PIX_FMT_YUV422P;
146 
147  code_vlc.table = code_table;
148  code_vlc.table_allocated = 1 << CODE_VLC_BITS;
149  init_vlc(&code_vlc, CODE_VLC_BITS, 16,
150  &code_tab[0][1], 4, 2,
151  &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
152 
153  return 0;
154 }
155 
157 {
158  WNV1Context * const l = avctx->priv_data;
159  AVFrame *pic = &l->pic;
160 
161  if (pic->data[0])
162  avctx->release_buffer(avctx, pic);
163 
164  return 0;
165 }
166 
168  .name = "wnv1",
169  .type = AVMEDIA_TYPE_VIDEO,
170  .id = AV_CODEC_ID_WNV1,
171  .priv_data_size = sizeof(WNV1Context),
172  .init = decode_init,
173  .close = decode_end,
174  .decode = decode_frame,
175  .capabilities = CODEC_CAP_DR1,
176  .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
177 };
GetBitContext gb
Definition: wnv1.c:38
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:61
This structure describes decoded (raw) audio or video data.
Definition: avcodec.h:989
void(* release_buffer)(struct AVCodecContext *c, AVFrame *pic)
Called to release buffers which were allocated with get_buffer.
Definition: avcodec.h:2259
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:237
int size
Definition: avcodec.h:916
AVCodec ff_wnv1_decoder
Definition: wnv1.c:167
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1533
#define VLC_TYPE
Definition: get_bits.h:61
AVCodec.
Definition: avcodec.h:2960
AVCodecContext * avctx
Definition: wnv1.c:34
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:228
uint8_t
const char data[16]
Definition: mxf.c:66
uint8_t * data
Definition: avcodec.h:915
bitstream reader API header.
static av_cold int decode_end(AVCodecContext *avctx)
Definition: wnv1.c:156
static int init(AVCodecParserContext *s)
Definition: h264_parser.c:335
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: wnv1.c:61
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:139
AVFrame pic
Definition: wnv1.c:35
void av_log_ask_for_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message asking for a sample.
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:1132
#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
Definition: get_bits.h:63
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:69
#define CODE_VLC_BITS
Definition: wnv1.c:47
Definition: vf_drawbox.c:36
static int wnv1_get_code(WNV1Context *w, int base_value)
Definition: wnv1.c:51
struct WNV1Context WNV1Context
int width
picture width / height.
Definition: avcodec.h:1508
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame)
Get a buffer for a frame.
Definition: utils.c:464
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:515
#define INIT_VLC_USE_NEW_STATIC
Definition: get_bits.h:433
int table_allocated
Definition: get_bits.h:66
int shift
Definition: wnv1.c:37
external API header
int linesize[AV_NUM_DATA_POINTERS]
Size, in bytes, of the data for each picture/channel plane.
Definition: avcodec.h:1008
main external API structure.
Definition: avcodec.h:1339
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:326
static VLC code_vlc
Definition: wnv1.c:48
#define init_vlc(vlc, nb_bits, nb_codes,bits, bits_wrap, bits_size,codes, codes_wrap, codes_size,flags)
Definition: get_bits.h:418
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:372
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: avcodec.h:997
Definition: vf_drawbox.c:36
common internal api header.
static const uint16_t code_tab[16][2]
Definition: wnv1.c:41
void * priv_data
Definition: avcodec.h:1382
VLC_TYPE(* table)[2]
code, bits
Definition: get_bits.h:65
int key_frame
1 -> keyframe, 0-> not
Definition: avcodec.h:1058
static av_cold int decode_init(AVCodecContext *avctx)
Definition: wnv1.c:139
const uint8_t ff_reverse[256]
Definition: mathtables.c:70
This structure stores compressed data.
Definition: avcodec.h:898