diff options
Diffstat (limited to 'contrib/ffmpeg/libavcodec/wnv1.c')
| -rw-r--r-- | contrib/ffmpeg/libavcodec/wnv1.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavcodec/wnv1.c b/contrib/ffmpeg/libavcodec/wnv1.c new file mode 100644 index 000000000..46b31a5c5 --- /dev/null +++ b/contrib/ffmpeg/libavcodec/wnv1.c @@ -0,0 +1,146 @@ +/* + * Winnov WNV1 codec + * Copyright (c) 2005 Konstantin Shishkov + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +/** + * @file wnv1.c + * Winnov WNV1 codec. + */ + +#include "avcodec.h" +#include "common.h" +#include "bitstream.h" + + +typedef struct WNV1Context{ + AVCodecContext *avctx; + AVFrame pic; + + int shift; + GetBitContext gb; +} WNV1Context; + +static uint16_t code_tab[16][2]={ +{0x1FD,9}, {0xFD,8}, {0x7D,7}, {0x3D,6}, {0x1D,5}, {0x0D,4}, {0x005,3}, +{0x000,1}, +{0x004,3}, {0x0C,4}, {0x1C,5}, {0x3C,6}, {0x7C,7}, {0xFC,8}, {0x1FC,9}, {0xFF,8} +}; + +#define CODE_VLC_BITS 9 +static VLC code_vlc; + +/* returns modified base_value */ +static inline int wnv1_get_code(WNV1Context *w, int base_value) +{ + int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1); + + if(v==15) + return ff_reverse[ get_bits(&w->gb, 8 - w->shift) ]; + else + return base_value + ((v - 7)<<w->shift); +} + +static int decode_frame(AVCodecContext *avctx, + void *data, int *data_size, + uint8_t *buf, int buf_size) +{ + WNV1Context * const l = avctx->priv_data; + AVFrame * const p= (AVFrame*)&l->pic; + unsigned char *Y,*U,*V; + int i, j; + int prev_y = 0, prev_u = 0, prev_v = 0; + + if(p->data[0]) + avctx->release_buffer(avctx, p); + + p->reference = 0; + if(avctx->get_buffer(avctx, p) < 0){ + av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); + return -1; + } + p->key_frame = 1; + + for(i=8; i<buf_size; i++) + buf[i]= ff_reverse[ buf[i] ]; //FIXME ensure that the buffer is modifyable or use a temp one + init_get_bits(&l->gb, buf+8, (buf_size-8)*8); + + if (buf[2] >> 4 == 6) + l->shift = 2; + else { + l->shift = 8 - (buf[2] >> 4); + if (l->shift > 4) { + av_log(avctx, AV_LOG_ERROR, "Unknown WNV1 frame header value %i, please upload file for study\n", buf[2] >> 4); + l->shift = 4; + } + if (l->shift < 1) { + av_log(avctx, AV_LOG_ERROR, "Unknown WNV1 frame header value %i, please upload file for study\n", buf[2] >> 4); + l->shift = 1; + } + } + + Y = p->data[0]; + U = p->data[1]; + V = p->data[2]; + for (j = 0; j < avctx->height; j++) { + for (i = 0; i < avctx->width / 2; i++) { + Y[i * 2] = wnv1_get_code(l, prev_y); + prev_u = U[i] = wnv1_get_code(l, prev_u); + prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]); + prev_v = V[i] = wnv1_get_code(l, prev_v); + } + Y += p->linesize[0]; + U += p->linesize[1]; + V += p->linesize[2]; + } + + + *data_size = sizeof(AVFrame); + *(AVFrame*)data = l->pic; + + return buf_size; +} + +static int decode_init(AVCodecContext *avctx){ + WNV1Context * const l = avctx->priv_data; + + l->avctx = avctx; + avctx->pix_fmt = PIX_FMT_YUV422P; + + if(!code_vlc.table){ + init_vlc(&code_vlc, CODE_VLC_BITS, 16, + &code_tab[0][1], 4, 2, + &code_tab[0][0], 4, 2, 1); + } + + return 0; +} + +AVCodec wnv1_decoder = { + "wnv1", + CODEC_TYPE_VIDEO, + CODEC_ID_WNV1, + sizeof(WNV1Context), + decode_init, + NULL, + NULL, + decode_frame, + CODEC_CAP_DR1, +}; |