3 * Copyright (c) 2011 Derek Buitenhuis
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 #define BITSTREAM_READER_LE
31 #include "huffyuvdsp.h"
36 AVCodecContext *avctx;
37 HuffYUVDSPContext hdsp;
40 uint8_t *val; /* First holds the lengths of vlc symbols and then their values */
43 static uint8_t vble_read_reverse_unary(GetBitContext *gb)
45 /* At most we need to read 9 bits total to get indices up to 8 */
46 uint8_t val = show_bits(gb, 8);
49 val = 7 - av_log2_16bit(ff_reverse[val]);
50 skip_bits(gb, val + 1);
58 /* Return something larger than 8 on error */
62 static int vble_unpack(VBLEContext *ctx, GetBitContext *gb)
66 /* Read all the lengths in first */
67 for (i = 0; i < ctx->size; i++) {
68 ctx->val[i] = vble_read_reverse_unary(gb);
70 if (ctx->val[i] == UINT8_MAX)
74 for (i = 0; i < ctx->size; i++) {
75 /* Check we have enough bits left */
76 if (get_bits_left(gb) < ctx->val[i])
79 /* get_bits can't take a length of 0 */
81 ctx->val[i] = (1 << ctx->val[i]) + get_bits(gb, ctx->val[i]) - 1;
87 static void vble_restore_plane(VBLEContext *ctx, AVFrame *pic,
88 int plane, int offset,
89 int width, int height)
91 uint8_t *dst = pic->data[plane];
92 uint8_t *val = ctx->val + offset;
93 int stride = pic->linesize[plane];
94 int i, j, left, left_top;
96 for (i = 0; i < height; i++) {
97 for (j = 0; j < width; j++)
98 val[j] = (val[j] >> 1) ^ -(val[j] & 1);
102 left_top = dst[-stride];
103 ctx->hdsp.add_hfyu_median_pred(dst, dst - stride, val,
104 width, &left, &left_top);
107 for (j = 1; j < width; j++)
108 dst[j] = val[j] + dst[j - 1];
115 static int vble_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
118 VBLEContext *ctx = avctx->priv_data;
121 const uint8_t *src = avpkt->data;
124 int width_uv = avctx->width / 2, height_uv = avctx->height / 2;
126 /* Allocate buffer */
127 if (ff_get_buffer(avctx, pic, 0) < 0) {
128 av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n");
129 return AVERROR(ENOMEM);
134 pic->pict_type = AV_PICTURE_TYPE_I;
136 /* Version should always be 1 */
137 version = AV_RL32(src);
140 av_log(avctx, AV_LOG_WARNING, "Unsupported VBLE Version: %d\n", version);
142 init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8);
145 if (vble_unpack(ctx, &gb) < 0) {
146 av_log(avctx, AV_LOG_ERROR, "Invalid Code\n");
147 return AVERROR_INVALIDDATA;
150 /* Restore planes. Should be almost identical to Huffyuv's. */
151 vble_restore_plane(ctx, pic, 0, offset, avctx->width, avctx->height);
154 if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
155 offset += avctx->width * avctx->height;
156 vble_restore_plane(ctx, pic, 1, offset, width_uv, height_uv);
158 offset += width_uv * height_uv;
159 vble_restore_plane(ctx, pic, 2, offset, width_uv, height_uv);
167 static av_cold int vble_decode_close(AVCodecContext *avctx)
169 VBLEContext *ctx = avctx->priv_data;
175 static av_cold int vble_decode_init(AVCodecContext *avctx)
177 VBLEContext *ctx = avctx->priv_data;
179 /* Stash for later use */
181 ff_huffyuvdsp_init(&ctx->hdsp);
183 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
184 avctx->bits_per_raw_sample = 8;
186 ctx->size = avpicture_get_size(avctx->pix_fmt,
187 avctx->width, avctx->height);
189 ctx->val = av_malloc(ctx->size * sizeof(*ctx->val));
192 av_log(avctx, AV_LOG_ERROR, "Could not allocate values buffer.\n");
193 vble_decode_close(avctx);
194 return AVERROR(ENOMEM);
200 AVCodec ff_vble_decoder = {
202 .long_name = NULL_IF_CONFIG_SMALL("VBLE Lossless Codec"),
203 .type = AVMEDIA_TYPE_VIDEO,
204 .id = AV_CODEC_ID_VBLE,
205 .priv_data_size = sizeof(VBLEContext),
206 .init = vble_decode_init,
207 .close = vble_decode_close,
208 .decode = vble_decode_frame,
209 .capabilities = CODEC_CAP_DR1,