| 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 | |
| 35 | typedef 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 | |
| 43 | static 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 | |
| 83 | static 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 | |
| 115 | static 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 | |
| 171 | static 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 | |
| 179 | static 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 | |
| 204 | AVCodec 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 | }; |