3 * Copyright (c) 2005 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
27 #define BITSTREAM_READER_LE
33 static const uint16_t code_tab[16][2] = {
34 { 0x17F, 9 }, { 0xBF, 8 }, { 0x5F, 7 }, { 0x2F, 6 }, { 0x17, 5 }, { 0x0B, 4 }, { 0x005, 3 },
36 { 0x01, 3 }, { 0x03, 4 }, { 0x07, 5 }, { 0x0F, 6 }, { 0x1F, 7 }, { 0x3F, 8 }, { 0x07F, 9 }, { 0xFF, 8 }
39 #define CODE_VLC_BITS 9
42 /* returns modified base_value */
43 static inline int wnv1_get_code(GetBitContext *gb, int shift, int base_value)
45 int v = get_vlc2(gb, code_vlc.table, CODE_VLC_BITS, 1);
48 return get_bits(gb, 8 - shift) << shift;
50 return base_value + ((v - 7U) << shift);
53 static int decode_frame(AVCodecContext *avctx,
54 void *data, int *got_frame,
57 const uint8_t *buf = avpkt->data;
58 int buf_size = avpkt->size;
59 AVFrame * const p = data;
61 unsigned char *Y,*U,*V;
63 int prev_y = 0, prev_u = 0, prev_v = 0;
65 if (buf_size < 8 + avctx->height * (avctx->width/2)/8) {
66 av_log(avctx, AV_LOG_ERROR, "Packet size %d is too small\n", buf_size);
67 return AVERROR_INVALIDDATA;
70 if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
74 if ((ret = init_get_bits8(&gb, buf + 8, buf_size - 8)) < 0)
80 shift = 8 - (buf[2] >> 4);
82 avpriv_request_sample(avctx,
83 "Unknown WNV1 frame header value %i",
88 avpriv_request_sample(avctx,
89 "Unknown WNV1 frame header value %i",
98 for (j = 0; j < avctx->height; j++) {
99 for (i = 0; i < avctx->width / 2; i++) {
100 Y[i * 2] = wnv1_get_code(&gb, shift, prev_y);
101 prev_u = U[i] = wnv1_get_code(&gb, shift, prev_u);
102 prev_y = Y[(i * 2) + 1] = wnv1_get_code(&gb, shift, Y[i * 2]);
103 prev_v = V[i] = wnv1_get_code(&gb, shift, prev_v);
116 static av_cold int decode_init(AVCodecContext *avctx)
118 static VLC_TYPE code_table[1 << CODE_VLC_BITS][2];
120 avctx->pix_fmt = AV_PIX_FMT_YUV422P;
122 code_vlc.table = code_table;
123 code_vlc.table_allocated = 1 << CODE_VLC_BITS;
124 init_vlc(&code_vlc, CODE_VLC_BITS, 16,
125 &code_tab[0][1], 4, 2,
126 &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
131 AVCodec ff_wnv1_decoder = {
133 .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
134 .type = AVMEDIA_TYPE_VIDEO,
135 .id = AV_CODEC_ID_WNV1,
137 .decode = decode_frame,
138 .capabilities = AV_CODEC_CAP_DR1,