| /* |
| * 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 |
| * Winnov WNV1 codec. |
| */ |
| |
| #include "libavutil/thread.h" |
| |
| #define BITSTREAM_READER_LE |
| #include "avcodec.h" |
| #include "get_bits.h" |
| #include "internal.h" |
| |
| static const uint8_t code_tab[16][2] = { |
| { 7, 1 }, { 8, 3 }, { 6, 3 }, { 9, 4 }, { 5, 4 }, { 10, 5 }, { 4, 5 }, |
| { 11, 6 }, { 3, 6 }, { 12, 7 }, { 2, 7 }, { 13, 8 }, { 1, 8 }, { 14, 9 }, |
| { 0, 9 }, { 15, 8 } |
| }; |
| |
| #define CODE_VLC_BITS 9 |
| static VLC code_vlc; |
| |
| /* returns modified base_value */ |
| static inline int wnv1_get_code(GetBitContext *gb, int shift, int base_value) |
| { |
| int v = get_vlc2(gb, code_vlc.table, CODE_VLC_BITS, 1); |
| |
| if (v == 8) |
| return get_bits(gb, 8 - shift) << shift; |
| else |
| return base_value + v * (1 << shift); |
| } |
| |
| static int decode_frame(AVCodecContext *avctx, |
| void *data, int *got_frame, |
| AVPacket *avpkt) |
| { |
| const uint8_t *buf = avpkt->data; |
| int buf_size = avpkt->size; |
| AVFrame * const p = data; |
| GetBitContext gb; |
| unsigned char *Y,*U,*V; |
| int i, j, ret, shift; |
| int prev_y = 0, prev_u = 0, prev_v = 0; |
| |
| if (buf_size < 8 + avctx->height * (avctx->width/2)/8) { |
| av_log(avctx, AV_LOG_ERROR, "Packet size %d is too small\n", buf_size); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if ((ret = ff_get_buffer(avctx, p, 0)) < 0) |
| return ret; |
| p->key_frame = 1; |
| |
| if ((ret = init_get_bits8(&gb, buf + 8, buf_size - 8)) < 0) |
| return ret; |
| |
| if (buf[2] >> 4 == 6) |
| shift = 2; |
| else { |
| shift = 8 - (buf[2] >> 4); |
| if (shift > 4) { |
| avpriv_request_sample(avctx, |
| "Unknown WNV1 frame header value %i", |
| buf[2] >> 4); |
| shift = 4; |
| } |
| if (shift < 1) { |
| avpriv_request_sample(avctx, |
| "Unknown WNV1 frame header value %i", |
| buf[2] >> 4); |
| 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(&gb, shift, prev_y); |
| prev_u = U[i] = wnv1_get_code(&gb, shift, prev_u); |
| prev_y = Y[(i * 2) + 1] = wnv1_get_code(&gb, shift, Y[i * 2]); |
| prev_v = V[i] = wnv1_get_code(&gb, shift, prev_v); |
| } |
| Y += p->linesize[0]; |
| U += p->linesize[1]; |
| V += p->linesize[2]; |
| } |
| |
| |
| *got_frame = 1; |
| |
| return buf_size; |
| } |
| |
| static av_cold void wnv1_init_static(void) |
| { |
| INIT_VLC_STATIC_FROM_LENGTHS(&code_vlc, CODE_VLC_BITS, 16, |
| &code_tab[0][1], 2, |
| &code_tab[0][0], 2, 1, |
| -7, INIT_VLC_OUTPUT_LE, 1 << CODE_VLC_BITS); |
| } |
| |
| static av_cold int decode_init(AVCodecContext *avctx) |
| { |
| static AVOnce init_static_once = AV_ONCE_INIT; |
| |
| avctx->pix_fmt = AV_PIX_FMT_YUV422P; |
| |
| ff_thread_once(&init_static_once, wnv1_init_static); |
| |
| return 0; |
| } |
| |
| AVCodec ff_wnv1_decoder = { |
| .name = "wnv1", |
| .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"), |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = AV_CODEC_ID_WNV1, |
| .init = decode_init, |
| .decode = decode_frame, |
| .capabilities = AV_CODEC_CAP_DR1, |
| .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, |
| }; |