FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/vble.c
Date: 2026-01-23 19:11:46
Exec Total Coverage
Lines: 70 78 89.7%
Functions: 5 5 100.0%
Branches: 26 34 76.5%
Line Branch Exec Source
1 /*
2 * VBLE Decoder
3 * Copyright (c) 2011 Derek Buitenhuis
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 * VBLE Decoder
25 */
26
27 #include "libavutil/imgutils.h"
28 #include "libavutil/mem.h"
29
30 #define BITSTREAM_READER_LE
31 #include "avcodec.h"
32 #include "codec_internal.h"
33 #include "get_bits.h"
34 #include "lossless_videodsp.h"
35 #include "thread.h"
36
37 typedef struct VBLEContext {
38 AVCodecContext *avctx;
39 LLVidDSPContext llviddsp;
40
41 int size;
42 uint8_t *val; ///< This array first holds the lengths of vlc symbols and then their value.
43 } VBLEContext;
44
45 5 static int vble_unpack(VBLEContext *ctx, GetBitContext *gb)
46 {
47 int i;
48 5 int allbits = 0;
49 static const uint8_t LUT[256] = {
50 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,
51 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,
52 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,
53 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,
54 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,
55 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,
56 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,
57 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,
58 };
59
60 /* Read all the lengths in first */
61
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 5888025 for (i = 0; i < ctx->size; i++) {
62 /* At most we need to read 9 bits total to get indices up to 8 */
63 5888021 int val = show_bits(gb, 8);
64
65 // read reverse unary
66
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 5888021 if (val) {
67 5887971 val = LUT[val];
68 5887971 skip_bits(gb, val + 1);
69 5887971 ctx->val[i] = val;
70 } else {
71 50 skip_bits(gb, 8);
72
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 50 if (!get_bits1(gb))
73 1 return -1;
74 49 ctx->val[i] = 8;
75 }
76 5888020 allbits += ctx->val[i];
77 }
78
79 /* Check we have enough bits left */
80
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 4 if (get_bits_left(gb) < allbits)
81 ✗ return -1;
82 4 return 0;
83 }
84
85 12 static void vble_restore_plane(VBLEContext *ctx, AVFrame *pic,
86 GetBitContext *gb, int plane,
87 int offset, int width, int height)
88 {
89 12 uint8_t *dst = pic->data[plane];
90 12 uint8_t *val = ctx->val + offset;
91 12 int stride = pic->linesize[plane];
92 int i, j, left, left_top;
93
94
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 5772 for (i = 0; i < height; i++) {
95
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 5535360 for (j = 0; j < width; j++) {
96 /* get_bits can't take a length of 0 */
97
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 5529600 if (val[j]) {
98 3143754 int v = (1 << val[j]) + get_bits(gb, val[j]) - 1;
99 3143754 val[j] = (v >> 1) ^ -(v & 1);
100 }
101 }
102
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 5760 if (i) {
103 5748 left = 0;
104 5748 left_top = dst[-stride];
105 5748 ctx->llviddsp.add_median_pred(dst, dst - stride, val,
106 width, &left, &left_top);
107 } else {
108 12 dst[0] = val[0];
109
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 10240 for (j = 1; j < width; j++)
110 10228 dst[j] = val[j] + dst[j - 1];
111 }
112 5760 dst += stride;
113 5760 val += width;
114 }
115 12 }
116
117 5 static int vble_decode_frame(AVCodecContext *avctx, AVFrame *pic,
118 int *got_frame, AVPacket *avpkt)
119 {
120 5 VBLEContext *ctx = avctx->priv_data;
121 GetBitContext gb;
122 5 const uint8_t *src = avpkt->data;
123 int version;
124 5 int offset = 0;
125 5 int width_uv = avctx->width / 2, height_uv = avctx->height / 2;
126 int ret;
127
128
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 5 if (avpkt->size < 4 || avpkt->size - 4 > INT_MAX/8) {
129 ✗ av_log(avctx, AV_LOG_ERROR, "Invalid packet size\n");
130 ✗ return AVERROR_INVALIDDATA;
131 }
132
133 /* Version should always be 1 */
134 5 version = AV_RL32(src);
135
136
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 5 if (version != 1)
137 ✗ av_log(avctx, AV_LOG_WARNING, "Unsupported VBLE Version: %d\n", version);
138
139 5 init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8);
140
141 /* Unpack */
142
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 5 if (vble_unpack(ctx, &gb) < 0) {
143 1 av_log(avctx, AV_LOG_ERROR, "Invalid Code\n");
144 1 return AVERROR_INVALIDDATA;
145 }
146
147 /* Allocate buffer */
148
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 4 if ((ret = ff_thread_get_buffer(avctx, pic, 0)) < 0)
149 ✗ return ret;
150
151 /* Restore planes. Should be almost identical to Huffyuv's. */
152 4 vble_restore_plane(ctx, pic, &gb, 0, offset, avctx->width, avctx->height);
153
154 /* Chroma */
155
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 4 if (!(ctx->avctx->flags & AV_CODEC_FLAG_GRAY)) {
156 4 offset += avctx->width * avctx->height;
157 4 vble_restore_plane(ctx, pic, &gb, 1, offset, width_uv, height_uv);
158
159 4 offset += width_uv * height_uv;
160 4 vble_restore_plane(ctx, pic, &gb, 2, offset, width_uv, height_uv);
161 }
162
163 4 *got_frame = 1;
164
165 4 return avpkt->size;
166 }
167
168 2 static av_cold int vble_decode_close(AVCodecContext *avctx)
169 {
170 2 VBLEContext *ctx = avctx->priv_data;
171 2 av_freep(&ctx->val);
172
173 2 return 0;
174 }
175
176 2 static av_cold int vble_decode_init(AVCodecContext *avctx)
177 {
178 2 VBLEContext *ctx = avctx->priv_data;
179
180 /* Stash for later use */
181 2 ctx->avctx = avctx;
182 2 ff_llviddsp_init(&ctx->llviddsp);
183
184 2 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
185 2 avctx->bits_per_raw_sample = 8;
186
187 2 ctx->size = av_image_get_buffer_size(avctx->pix_fmt,
188 avctx->width, avctx->height, 1);
189
190
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 2 if (ctx->size < 0)
191 ✗ return ctx->size;
192
193 2 ctx->val = av_malloc_array(ctx->size, sizeof(*ctx->val));
194
195
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 2 if (!ctx->val) {
196 ✗ av_log(avctx, AV_LOG_ERROR, "Could not allocate values buffer.\n");
197 ✗ return AVERROR(ENOMEM);
198 }
199
200 2 return 0;
201 }
202
203 const FFCodec ff_vble_decoder = {
204 .p.name = "vble",
205 CODEC_LONG_NAME("VBLE Lossless Codec"),
206 .p.type = AVMEDIA_TYPE_VIDEO,
207 .p.id = AV_CODEC_ID_VBLE,
208 .priv_data_size = sizeof(VBLEContext),
209 .init = vble_decode_init,
210 .close = vble_decode_close,
211 FF_CODEC_DECODE_CB(vble_decode_frame),
212 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
213 };
214