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#define BITSTREAM_READER_LE
28
29#include "avcodec.h"
30#include "get_bits.h"
31#include "huffyuvdsp.h"
32#include "internal.h"
33#include "mathops.h"
34
35typedef struct {
36    AVCodecContext *avctx;
37    HuffYUVDSPContext hdsp;
38
39    int            size;
40    uint8_t        *val; ///< This array first holds the lengths of vlc symbols and then their value.
41} VBLEContext;
42
43static int vble_unpack(VBLEContext *ctx, GetBitContext *gb)
44{
45    int i;
46    int allbits = 0;
47    static const uint8_t LUT[256] = {
48        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,
49        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,
50        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,
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        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,
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        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,
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    };
57
58    /* Read all the lengths in first */
59    for (i = 0; i < ctx->size; i++) {
60        /* At most we need to read 9 bits total to get indices up to 8 */
61        int val = show_bits(gb, 8);
62
63        // read reverse unary
64        if (val) {
65            val = LUT[val];
66            skip_bits(gb, val + 1);
67            ctx->val[i] = val;
68        } else {
69            skip_bits(gb, 8);
70            if (!get_bits1(gb))
71                return -1;
72            ctx->val[i] = 8;
73        }
74        allbits += ctx->val[i];
75    }
76
77    /* Check we have enough bits left */
78    if (get_bits_left(gb) < allbits)
79        return -1;
80    return 0;
81}
82
83static void vble_restore_plane(VBLEContext *ctx, AVFrame *pic,
84                               GetBitContext *gb, int plane,
85                               int offset, int width, int height)
86{
87    uint8_t *dst = pic->data[plane];
88    uint8_t *val = ctx->val + offset;
89    int stride = pic->linesize[plane];
90    int i, j, left, left_top;
91
92    for (i = 0; i < height; i++) {
93        for (j = 0; j < width; j++) {
94            /* get_bits can't take a length of 0 */
95            if (val[j]) {
96                int v = (1 << val[j]) + get_bits(gb, val[j]) - 1;
97                val[j] = (v >> 1) ^ -(v & 1);
98            }
99        }
100        if (i) {
101            left = 0;
102            left_top = dst[-stride];
103            ctx->hdsp.add_hfyu_median_pred(dst, dst - stride, val,
104                                           width, &left, &left_top);
105        } else {
106            dst[0] = val[0];
107            for (j = 1; j < width; j++)
108                dst[j] = val[j] + dst[j - 1];
109        }
110        dst += stride;
111        val += width;
112    }
113}
114
115static int vble_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
116                             AVPacket *avpkt)
117{
118    VBLEContext *ctx = avctx->priv_data;
119    AVFrame *pic     = data;
120    GetBitContext gb;
121    const uint8_t *src = avpkt->data;
122    int version;
123    int offset = 0;
124    int width_uv = avctx->width / 2, height_uv = avctx->height / 2;
125    int ret;
126
127    if (avpkt->size < 4 || avpkt->size - 4 > INT_MAX/8) {
128        av_log(avctx, AV_LOG_ERROR, "Invalid packet size\n");
129        return AVERROR_INVALIDDATA;
130    }
131
132    /* Allocate buffer */
133    if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
134        return ret;
135
136    /* Set flags */
137    pic->key_frame = 1;
138    pic->pict_type = AV_PICTURE_TYPE_I;
139
140    /* Version should always be 1 */
141    version = AV_RL32(src);
142
143    if (version != 1)
144        av_log(avctx, AV_LOG_WARNING, "Unsupported VBLE Version: %d\n", version);
145
146    init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8);
147
148    /* Unpack */
149    if (vble_unpack(ctx, &gb) < 0) {
150        av_log(avctx, AV_LOG_ERROR, "Invalid Code\n");
151        return AVERROR_INVALIDDATA;
152    }
153
154    /* Restore planes. Should be almost identical to Huffyuv's. */
155    vble_restore_plane(ctx, pic, &gb, 0, offset, avctx->width, avctx->height);
156
157    /* Chroma */
158    if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
159        offset += avctx->width * avctx->height;
160        vble_restore_plane(ctx, pic, &gb, 1, offset, width_uv, height_uv);
161
162        offset += width_uv * height_uv;
163        vble_restore_plane(ctx, pic, &gb, 2, offset, width_uv, height_uv);
164    }
165
166    *got_frame       = 1;
167
168    return avpkt->size;
169}
170
171static av_cold int vble_decode_close(AVCodecContext *avctx)
172{
173    VBLEContext *ctx = avctx->priv_data;
174    av_freep(&ctx->val);
175
176    return 0;
177}
178
179static av_cold int vble_decode_init(AVCodecContext *avctx)
180{
181    VBLEContext *ctx = avctx->priv_data;
182
183    /* Stash for later use */
184    ctx->avctx = avctx;
185    ff_huffyuvdsp_init(&ctx->hdsp);
186
187    avctx->pix_fmt = AV_PIX_FMT_YUV420P;
188    avctx->bits_per_raw_sample = 8;
189
190    ctx->size = avpicture_get_size(avctx->pix_fmt,
191                                   avctx->width, avctx->height);
192
193    ctx->val = av_malloc_array(ctx->size, sizeof(*ctx->val));
194
195    if (!ctx->val) {
196        av_log(avctx, AV_LOG_ERROR, "Could not allocate values buffer.\n");
197        vble_decode_close(avctx);
198        return AVERROR(ENOMEM);
199    }
200
201    return 0;
202}
203
204AVCodec ff_vble_decoder = {
205    .name           = "vble",
206    .long_name      = NULL_IF_CONFIG_SMALL("VBLE Lossless Codec"),
207    .type           = AVMEDIA_TYPE_VIDEO,
208    .id             = AV_CODEC_ID_VBLE,
209    .priv_data_size = sizeof(VBLEContext),
210    .init           = vble_decode_init,
211    .close          = vble_decode_close,
212    .decode         = vble_decode_frame,
213    .capabilities   = CODEC_CAP_DR1,
214};
215