Details | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4349 | Serge | 1 | /* |
| 2 | * Winnov WNV1 codec |
||
| 3 | * Copyright (c) 2005 Konstantin Shishkov |
||
| 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 | * Winnov WNV1 codec. |
||
| 25 | */ |
||
| 26 | |||
| 27 | #include "avcodec.h" |
||
| 28 | #include "get_bits.h" |
||
| 29 | #include "internal.h" |
||
| 30 | #include "mathops.h" |
||
| 31 | |||
| 32 | |||
| 33 | typedef struct WNV1Context { |
||
| 34 | int shift; |
||
| 35 | GetBitContext gb; |
||
| 36 | } WNV1Context; |
||
| 37 | |||
| 38 | static const uint16_t code_tab[16][2] = { |
||
| 39 | { 0x1FD, 9 }, { 0xFD, 8 }, { 0x7D, 7 }, { 0x3D, 6 }, { 0x1D, 5 }, { 0x0D, 4 }, { 0x005, 3 }, |
||
| 40 | { 0x000, 1 }, |
||
| 41 | { 0x004, 3 }, { 0x0C, 4 }, { 0x1C, 5 }, { 0x3C, 6 }, { 0x7C, 7 }, { 0xFC, 8 }, { 0x1FC, 9 }, { 0xFF, 8 } |
||
| 42 | }; |
||
| 43 | |||
| 44 | #define CODE_VLC_BITS 9 |
||
| 45 | static VLC code_vlc; |
||
| 46 | |||
| 47 | /* returns modified base_value */ |
||
| 48 | static inline int wnv1_get_code(WNV1Context *w, int base_value) |
||
| 49 | { |
||
| 50 | int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1); |
||
| 51 | |||
| 52 | if (v == 15) |
||
| 53 | return ff_reverse[get_bits(&w->gb, 8 - w->shift)]; |
||
| 54 | else |
||
| 55 | return base_value + ((v - 7) << w->shift); |
||
| 56 | } |
||
| 57 | |||
| 58 | static int decode_frame(AVCodecContext *avctx, |
||
| 59 | void *data, int *got_frame, |
||
| 60 | AVPacket *avpkt) |
||
| 61 | { |
||
| 62 | WNV1Context * const l = avctx->priv_data; |
||
| 63 | const uint8_t *buf = avpkt->data; |
||
| 64 | int buf_size = avpkt->size; |
||
| 65 | AVFrame * const p = data; |
||
| 66 | unsigned char *Y,*U,*V; |
||
| 67 | int i, j, ret; |
||
| 68 | int prev_y = 0, prev_u = 0, prev_v = 0; |
||
| 69 | uint8_t *rbuf; |
||
| 70 | |||
| 71 | if (buf_size <= 8) { |
||
| 72 | av_log(avctx, AV_LOG_ERROR, "Packet size %d is too small\n", buf_size); |
||
| 73 | return AVERROR_INVALIDDATA; |
||
| 74 | } |
||
| 75 | |||
| 76 | rbuf = av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE); |
||
| 77 | if (!rbuf) { |
||
| 78 | av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n"); |
||
| 79 | return AVERROR(ENOMEM); |
||
| 80 | } |
||
| 81 | |||
| 82 | if ((ret = ff_get_buffer(avctx, p, 0)) < 0) { |
||
| 83 | av_free(rbuf); |
||
| 84 | return ret; |
||
| 85 | } |
||
| 86 | p->key_frame = 1; |
||
| 87 | |||
| 88 | for (i = 8; i < buf_size; i++) |
||
| 89 | rbuf[i] = ff_reverse[buf[i]]; |
||
| 90 | init_get_bits(&l->gb, rbuf + 8, (buf_size - 8) * 8); |
||
| 91 | |||
| 92 | if (buf[2] >> 4 == 6) |
||
| 93 | l->shift = 2; |
||
| 94 | else { |
||
| 95 | l->shift = 8 - (buf[2] >> 4); |
||
| 96 | if (l->shift > 4) { |
||
| 97 | avpriv_request_sample(avctx, |
||
| 98 | "Unknown WNV1 frame header value %i", |
||
| 99 | buf[2] >> 4); |
||
| 100 | l->shift = 4; |
||
| 101 | } |
||
| 102 | if (l->shift < 1) { |
||
| 103 | avpriv_request_sample(avctx, |
||
| 104 | "Unknown WNV1 frame header value %i", |
||
| 105 | buf[2] >> 4); |
||
| 106 | l->shift = 1; |
||
| 107 | } |
||
| 108 | } |
||
| 109 | |||
| 110 | Y = p->data[0]; |
||
| 111 | U = p->data[1]; |
||
| 112 | V = p->data[2]; |
||
| 113 | for (j = 0; j < avctx->height; j++) { |
||
| 114 | for (i = 0; i < avctx->width / 2; i++) { |
||
| 115 | Y[i * 2] = wnv1_get_code(l, prev_y); |
||
| 116 | prev_u = U[i] = wnv1_get_code(l, prev_u); |
||
| 117 | prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]); |
||
| 118 | prev_v = V[i] = wnv1_get_code(l, prev_v); |
||
| 119 | } |
||
| 120 | Y += p->linesize[0]; |
||
| 121 | U += p->linesize[1]; |
||
| 122 | V += p->linesize[2]; |
||
| 123 | } |
||
| 124 | |||
| 125 | |||
| 126 | *got_frame = 1; |
||
| 127 | av_free(rbuf); |
||
| 128 | |||
| 129 | return buf_size; |
||
| 130 | } |
||
| 131 | |||
| 132 | static av_cold int decode_init(AVCodecContext *avctx) |
||
| 133 | { |
||
| 134 | static VLC_TYPE code_table[1 << CODE_VLC_BITS][2]; |
||
| 135 | |||
| 136 | avctx->pix_fmt = AV_PIX_FMT_YUV422P; |
||
| 137 | |||
| 138 | code_vlc.table = code_table; |
||
| 139 | code_vlc.table_allocated = 1 << CODE_VLC_BITS; |
||
| 140 | init_vlc(&code_vlc, CODE_VLC_BITS, 16, |
||
| 141 | &code_tab[0][1], 4, 2, |
||
| 142 | &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC); |
||
| 143 | |||
| 144 | return 0; |
||
| 145 | } |
||
| 146 | |||
| 147 | AVCodec ff_wnv1_decoder = { |
||
| 148 | .name = "wnv1", |
||
| 149 | .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"), |
||
| 150 | .type = AVMEDIA_TYPE_VIDEO, |
||
| 151 | .id = AV_CODEC_ID_WNV1, |
||
| 152 | .priv_data_size = sizeof(WNV1Context), |
||
| 153 | .init = decode_init, |
||
| 154 | .decode = decode_frame, |
||
| 155 | .capabilities = CODEC_CAP_DR1, |
||
| 156 | }; |