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
29 #define BITSTREAM_READER_LE
30 #include "avcodec.h"
31 #include "get_bits.h"
32 #include "internal.h"
33 #include "lossless_videodsp.h"
34 #include "mathops.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
vble_unpack(VBLEContext * ctx,GetBitContext * gb)45 static int vble_unpack(VBLEContext *ctx, GetBitContext *gb)
46 {
47 int i;
48 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 for (i = 0; i < ctx->size; i++) {
62 /* At most we need to read 9 bits total to get indices up to 8 */
63 int val = show_bits(gb, 8);
64
65 // read reverse unary
66 if (val) {
67 val = LUT[val];
68 skip_bits(gb, val + 1);
69 ctx->val[i] = val;
70 } else {
71 skip_bits(gb, 8);
72 if (!get_bits1(gb))
73 return -1;
74 ctx->val[i] = 8;
75 }
76 allbits += ctx->val[i];
77 }
78
79 /* Check we have enough bits left */
80 if (get_bits_left(gb) < allbits)
81 return -1;
82 return 0;
83 }
84
vble_restore_plane(VBLEContext * ctx,AVFrame * pic,GetBitContext * gb,int plane,int offset,int width,int height)85 static void vble_restore_plane(VBLEContext *ctx, AVFrame *pic,
86 GetBitContext *gb, int plane,
87 int offset, int width, int height)
88 {
89 uint8_t *dst = pic->data[plane];
90 uint8_t *val = ctx->val + offset;
91 int stride = pic->linesize[plane];
92 int i, j, left, left_top;
93
94 for (i = 0; i < height; i++) {
95 for (j = 0; j < width; j++) {
96 /* get_bits can't take a length of 0 */
97 if (val[j]) {
98 int v = (1 << val[j]) + get_bits(gb, val[j]) - 1;
99 val[j] = (v >> 1) ^ -(v & 1);
100 }
101 }
102 if (i) {
103 left = 0;
104 left_top = dst[-stride];
105 ctx->llviddsp.add_median_pred(dst, dst - stride, val,
106 width, &left, &left_top);
107 } else {
108 dst[0] = val[0];
109 for (j = 1; j < width; j++)
110 dst[j] = val[j] + dst[j - 1];
111 }
112 dst += stride;
113 val += width;
114 }
115 }
116
vble_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)117 static int vble_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
118 AVPacket *avpkt)
119 {
120 VBLEContext *ctx = avctx->priv_data;
121 AVFrame *pic = data;
122 GetBitContext gb;
123 const uint8_t *src = avpkt->data;
124 int version;
125 int offset = 0;
126 int width_uv = avctx->width / 2, height_uv = avctx->height / 2;
127 int ret;
128 ThreadFrame frame = { .f = data };
129
130 if (avpkt->size < 4 || avpkt->size - 4 > INT_MAX/8) {
131 av_log(avctx, AV_LOG_ERROR, "Invalid packet size\n");
132 return AVERROR_INVALIDDATA;
133 }
134
135 /* Allocate buffer */
136 if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
137 return ret;
138
139 /* Set flags */
140 pic->key_frame = 1;
141 pic->pict_type = AV_PICTURE_TYPE_I;
142
143 /* Version should always be 1 */
144 version = AV_RL32(src);
145
146 if (version != 1)
147 av_log(avctx, AV_LOG_WARNING, "Unsupported VBLE Version: %d\n", version);
148
149 init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8);
150
151 /* Unpack */
152 if (vble_unpack(ctx, &gb) < 0) {
153 av_log(avctx, AV_LOG_ERROR, "Invalid Code\n");
154 return AVERROR_INVALIDDATA;
155 }
156
157 /* Restore planes. Should be almost identical to Huffyuv's. */
158 vble_restore_plane(ctx, pic, &gb, 0, offset, avctx->width, avctx->height);
159
160 /* Chroma */
161 if (!(ctx->avctx->flags & AV_CODEC_FLAG_GRAY)) {
162 offset += avctx->width * avctx->height;
163 vble_restore_plane(ctx, pic, &gb, 1, offset, width_uv, height_uv);
164
165 offset += width_uv * height_uv;
166 vble_restore_plane(ctx, pic, &gb, 2, offset, width_uv, height_uv);
167 }
168
169 *got_frame = 1;
170
171 return avpkt->size;
172 }
173
vble_decode_close(AVCodecContext * avctx)174 static av_cold int vble_decode_close(AVCodecContext *avctx)
175 {
176 VBLEContext *ctx = avctx->priv_data;
177 av_freep(&ctx->val);
178
179 return 0;
180 }
181
vble_decode_init(AVCodecContext * avctx)182 static av_cold int vble_decode_init(AVCodecContext *avctx)
183 {
184 VBLEContext *ctx = avctx->priv_data;
185
186 /* Stash for later use */
187 ctx->avctx = avctx;
188 ff_llviddsp_init(&ctx->llviddsp);
189
190 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
191 avctx->bits_per_raw_sample = 8;
192
193 ctx->size = av_image_get_buffer_size(avctx->pix_fmt,
194 avctx->width, avctx->height, 1);
195
196 ctx->val = av_malloc_array(ctx->size, sizeof(*ctx->val));
197
198 if (!ctx->val) {
199 av_log(avctx, AV_LOG_ERROR, "Could not allocate values buffer.\n");
200 return AVERROR(ENOMEM);
201 }
202
203 return 0;
204 }
205
206 AVCodec ff_vble_decoder = {
207 .name = "vble",
208 .long_name = NULL_IF_CONFIG_SMALL("VBLE Lossless Codec"),
209 .type = AVMEDIA_TYPE_VIDEO,
210 .id = AV_CODEC_ID_VBLE,
211 .priv_data_size = sizeof(VBLEContext),
212 .init = vble_decode_init,
213 .close = vble_decode_close,
214 .decode = vble_decode_frame,
215 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
216 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
217 };
218