yading@10: /* yading@10: * Winnov WNV1 codec yading@10: * Copyright (c) 2005 Konstantin Shishkov yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: /** yading@10: * @file yading@10: * Winnov WNV1 codec. yading@10: */ yading@10: yading@10: #include "avcodec.h" yading@10: #include "get_bits.h" yading@10: #include "internal.h" yading@10: #include "mathops.h" yading@10: yading@10: yading@10: typedef struct WNV1Context { yading@10: AVCodecContext *avctx; yading@10: yading@10: int shift; yading@10: GetBitContext gb; yading@10: } WNV1Context; yading@10: yading@10: static const uint16_t code_tab[16][2] = { yading@10: { 0x1FD, 9 }, { 0xFD, 8 }, { 0x7D, 7 }, { 0x3D, 6 }, { 0x1D, 5 }, { 0x0D, 4 }, { 0x005, 3 }, yading@10: { 0x000, 1 }, yading@10: { 0x004, 3 }, { 0x0C, 4 }, { 0x1C, 5 }, { 0x3C, 6 }, { 0x7C, 7 }, { 0xFC, 8 }, { 0x1FC, 9 }, { 0xFF, 8 } yading@10: }; yading@10: yading@10: #define CODE_VLC_BITS 9 yading@10: static VLC code_vlc; yading@10: yading@10: /* returns modified base_value */ yading@10: static inline int wnv1_get_code(WNV1Context *w, int base_value) yading@10: { yading@10: int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1); yading@10: yading@10: if (v == 15) yading@10: return ff_reverse[get_bits(&w->gb, 8 - w->shift)]; yading@10: else yading@10: return base_value + ((v - 7) << w->shift); yading@10: } yading@10: yading@10: static int decode_frame(AVCodecContext *avctx, yading@10: void *data, int *got_frame, yading@10: AVPacket *avpkt) yading@10: { yading@10: WNV1Context * const l = avctx->priv_data; yading@10: const uint8_t *buf = avpkt->data; yading@10: int buf_size = avpkt->size; yading@10: AVFrame * const p = data; yading@10: unsigned char *Y,*U,*V; yading@10: int i, j, ret; yading@10: int prev_y = 0, prev_u = 0, prev_v = 0; yading@10: uint8_t *rbuf; yading@10: yading@10: if(buf_size<=8) { yading@10: av_log(avctx, AV_LOG_ERROR, "buf_size %d is too small\n", buf_size); yading@10: return AVERROR_INVALIDDATA; yading@10: } yading@10: yading@10: rbuf = av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE); yading@10: if (!rbuf) { yading@10: av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n"); yading@10: return AVERROR(ENOMEM); yading@10: } yading@10: yading@10: if ((ret = ff_get_buffer(avctx, p, 0)) < 0) { yading@10: av_free(rbuf); yading@10: return ret; yading@10: } yading@10: p->key_frame = 1; yading@10: yading@10: for (i = 8; i < buf_size; i++) yading@10: rbuf[i] = ff_reverse[buf[i]]; yading@10: init_get_bits(&l->gb, rbuf + 8, (buf_size - 8) * 8); yading@10: yading@10: if (buf[2] >> 4 == 6) yading@10: l->shift = 2; yading@10: else { yading@10: l->shift = 8 - (buf[2] >> 4); yading@10: if (l->shift > 4) { yading@10: avpriv_request_sample(avctx, yading@10: "Unknown WNV1 frame header value %i", yading@10: buf[2] >> 4); yading@10: l->shift = 4; yading@10: } yading@10: if (l->shift < 1) { yading@10: avpriv_request_sample(avctx, yading@10: "Unknown WNV1 frame header value %i", yading@10: buf[2] >> 4); yading@10: l->shift = 1; yading@10: } yading@10: } yading@10: yading@10: Y = p->data[0]; yading@10: U = p->data[1]; yading@10: V = p->data[2]; yading@10: for (j = 0; j < avctx->height; j++) { yading@10: for (i = 0; i < avctx->width / 2; i++) { yading@10: Y[i * 2] = wnv1_get_code(l, prev_y); yading@10: prev_u = U[i] = wnv1_get_code(l, prev_u); yading@10: prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]); yading@10: prev_v = V[i] = wnv1_get_code(l, prev_v); yading@10: } yading@10: Y += p->linesize[0]; yading@10: U += p->linesize[1]; yading@10: V += p->linesize[2]; yading@10: } yading@10: yading@10: yading@10: *got_frame = 1; yading@10: av_free(rbuf); yading@10: yading@10: return buf_size; yading@10: } yading@10: yading@10: static av_cold int decode_init(AVCodecContext *avctx) yading@10: { yading@10: WNV1Context * const l = avctx->priv_data; yading@10: static VLC_TYPE code_table[1 << CODE_VLC_BITS][2]; yading@10: yading@10: l->avctx = avctx; yading@10: avctx->pix_fmt = AV_PIX_FMT_YUV422P; yading@10: yading@10: code_vlc.table = code_table; yading@10: code_vlc.table_allocated = 1 << CODE_VLC_BITS; yading@10: init_vlc(&code_vlc, CODE_VLC_BITS, 16, yading@10: &code_tab[0][1], 4, 2, yading@10: &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC); yading@10: yading@10: return 0; yading@10: } yading@10: yading@10: AVCodec ff_wnv1_decoder = { yading@10: .name = "wnv1", yading@10: .type = AVMEDIA_TYPE_VIDEO, yading@10: .id = AV_CODEC_ID_WNV1, yading@10: .priv_data_size = sizeof(WNV1Context), yading@10: .init = decode_init, yading@10: .decode = decode_frame, yading@10: .capabilities = CODEC_CAP_DR1, yading@10: .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"), yading@10: };