1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
/*
* VBLE Decoder
* Copyright (c) 2011 Derek Buitenhuis
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* VBLE Decoder
*/
#define BITSTREAM_READER_LE
#include "avcodec.h"
#include "dsputil.h"
#include "get_bits.h"
#include "internal.h"
#include "mathops.h"
typedef struct {
AVCodecContext *avctx;
DSPContext dsp;
int size;
uint8_t *val; ///< This array first holds the lengths of vlc symbols and then their value.
} VBLEContext;
static int vble_unpack(VBLEContext *ctx, GetBitContext *gb)
{
int i;
int allbits = 0;
static const uint8_t LUT[256] = {
8,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
7,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
};
/* Read all the lengths in first */
for (i = 0; i < ctx->size; i++) {
/* At most we need to read 9 bits total to get indices up to 8 */
int val = show_bits(gb, 8);
// read reverse unary
if (val) {
val = LUT[val];
skip_bits(gb, val + 1);
ctx->val[i] = val;
} else {
skip_bits(gb, 8);
if (!get_bits1(gb))
return -1;
ctx->val[i] = 8;
}
allbits += ctx->val[i];
}
/* Check we have enough bits left */
if (get_bits_left(gb) < allbits)
return -1;
return 0;
}
static void vble_restore_plane(VBLEContext *ctx, AVFrame *pic,
GetBitContext *gb, int plane,
int offset, int width, int height)
{
uint8_t *dst = pic->data[plane];
uint8_t *val = ctx->val + offset;
int stride = pic->linesize[plane];
int i, j, left, left_top;
for (i = 0; i < height; i++) {
for (j = 0; j < width; j++) {
/* get_bits can't take a length of 0 */
if (val[j]) {
int v = (1 << val[j]) + get_bits(gb, val[j]) - 1;
val[j] = (v >> 1) ^ -(v & 1);
}
}
if (i) {
left = 0;
left_top = dst[-stride];
ctx->dsp.add_hfyu_median_prediction(dst, dst-stride, val, width, &left, &left_top);
} else {
dst[0] = val[0];
for (j = 1; j < width; j++)
dst[j] = val[j] + dst[j - 1];
}
dst += stride;
val += width;
}
}
static int vble_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
AVPacket *avpkt)
{
VBLEContext *ctx = avctx->priv_data;
AVFrame *pic = data;
GetBitContext gb;
const uint8_t *src = avpkt->data;
int version;
int offset = 0;
int width_uv = avctx->width / 2, height_uv = avctx->height / 2;
int ret;
if (avpkt->size < 4 || avpkt->size - 4 > INT_MAX/8) {
av_log(avctx, AV_LOG_ERROR, "Invalid packet size\n");
return AVERROR_INVALIDDATA;
}
/* Allocate buffer */
if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
return ret;
/* Set flags */
pic->key_frame = 1;
pic->pict_type = AV_PICTURE_TYPE_I;
/* Version should always be 1 */
version = AV_RL32(src);
if (version != 1)
av_log(avctx, AV_LOG_WARNING, "Unsupported VBLE Version: %d\n", version);
init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8);
/* Unpack */
if (vble_unpack(ctx, &gb) < 0) {
av_log(avctx, AV_LOG_ERROR, "Invalid Code\n");
return AVERROR_INVALIDDATA;
}
/* Restore planes. Should be almost identical to Huffyuv's. */
vble_restore_plane(ctx, pic, &gb, 0, offset, avctx->width, avctx->height);
/* Chroma */
if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
offset += avctx->width * avctx->height;
vble_restore_plane(ctx, pic, &gb, 1, offset, width_uv, height_uv);
offset += width_uv * height_uv;
vble_restore_plane(ctx, pic, &gb, 2, offset, width_uv, height_uv);
}
*got_frame = 1;
return avpkt->size;
}
static av_cold int vble_decode_close(AVCodecContext *avctx)
{
VBLEContext *ctx = avctx->priv_data;
av_freep(&ctx->val);
return 0;
}
static av_cold int vble_decode_init(AVCodecContext *avctx)
{
VBLEContext *ctx = avctx->priv_data;
/* Stash for later use */
ctx->avctx = avctx;
ff_dsputil_init(&ctx->dsp, avctx);
avctx->pix_fmt = AV_PIX_FMT_YUV420P;
avctx->bits_per_raw_sample = 8;
ctx->size = avpicture_get_size(avctx->pix_fmt,
avctx->width, avctx->height);
ctx->val = av_malloc_array(ctx->size, sizeof(*ctx->val));
if (!ctx->val) {
av_log(avctx, AV_LOG_ERROR, "Could not allocate values buffer.\n");
vble_decode_close(avctx);
return AVERROR(ENOMEM);
}
return 0;
}
AVCodec ff_vble_decoder = {
.name = "vble",
.long_name = NULL_IF_CONFIG_SMALL("VBLE Lossless Codec"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_VBLE,
.priv_data_size = sizeof(VBLEContext),
.init = vble_decode_init,
.close = vble_decode_close,
.decode = vble_decode_frame,
.capabilities = CODEC_CAP_DR1,
};
|
