1/* 2 * Creative YUV (CYUV) Video Decoder 3 * by Mike Melanson (melanson@pcisys.net) 4 * based on "Creative YUV (CYUV) stream format for AVI": 5 * http://www.csse.monash.edu.au/~timf/videocodec/cyuv.txt 6 * 7 * Copyright (C) 2003 the ffmpeg project 8 * 9 * This file is part of FFmpeg. 10 * 11 * FFmpeg is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU Lesser General Public 13 * License as published by the Free Software Foundation; either 14 * version 2.1 of the License, or (at your option) any later version. 15 * 16 * FFmpeg is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 19 * Lesser General Public License for more details. 20 * 21 * You should have received a copy of the GNU Lesser General Public 22 * License along with FFmpeg; if not, write to the Free Software 23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 24 */ 25 26/** 27 * @file 28 * Creative YUV (CYUV) Video Decoder. 29 */ 30 31#include <stdio.h> 32#include <stdlib.h> 33#include <string.h> 34 35#include "avcodec.h" 36#include "internal.h" 37#include "libavutil/internal.h" 38 39 40typedef struct CyuvDecodeContext { 41 AVCodecContext *avctx; 42 int width, height; 43} CyuvDecodeContext; 44 45static av_cold int cyuv_decode_init(AVCodecContext *avctx) 46{ 47 CyuvDecodeContext *s = avctx->priv_data; 48 49 s->avctx = avctx; 50 s->width = avctx->width; 51 /* width needs to be divisible by 4 for this codec to work */ 52 if (s->width & 0x3) 53 return AVERROR_INVALIDDATA; 54 s->height = avctx->height; 55 56 return 0; 57} 58 59static int cyuv_decode_frame(AVCodecContext *avctx, 60 void *data, int *got_frame, 61 AVPacket *avpkt) 62{ 63 const uint8_t *buf = avpkt->data; 64 int buf_size = avpkt->size; 65 CyuvDecodeContext *s=avctx->priv_data; 66 AVFrame *frame = data; 67 68 unsigned char *y_plane; 69 unsigned char *u_plane; 70 unsigned char *v_plane; 71 int y_ptr; 72 int u_ptr; 73 int v_ptr; 74 75 /* prediction error tables (make it clear that they are signed values) */ 76 const signed char *y_table = (const signed char*)buf + 0; 77 const signed char *u_table = (const signed char*)buf + 16; 78 const signed char *v_table = (const signed char*)buf + 32; 79 80 unsigned char y_pred, u_pred, v_pred; 81 int stream_ptr; 82 unsigned char cur_byte; 83 int pixel_groups; 84 int rawsize = s->height * FFALIGN(s->width,2) * 2; 85 int ret; 86 87 if (avctx->codec_id == AV_CODEC_ID_AURA) { 88 y_table = u_table; 89 u_table = v_table; 90 } 91 /* sanity check the buffer size: A buffer has 3x16-bytes tables 92 * followed by (height) lines each with 3 bytes to represent groups 93 * of 4 pixels. Thus, the total size of the buffer ought to be: 94 * (3 * 16) + height * (width * 3 / 4) */ 95 if (buf_size == 48 + s->height * (s->width * 3 / 4)) { 96 avctx->pix_fmt = AV_PIX_FMT_YUV411P; 97 } else if(buf_size == rawsize ) { 98 avctx->pix_fmt = AV_PIX_FMT_UYVY422; 99 } else { 100 av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n", 101 buf_size, 48 + s->height * (s->width * 3 / 4)); 102 return AVERROR_INVALIDDATA; 103 } 104 105 /* pixel data starts 48 bytes in, after 3x16-byte tables */ 106 stream_ptr = 48; 107 108 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 109 return ret; 110 111 y_plane = frame->data[0]; 112 u_plane = frame->data[1]; 113 v_plane = frame->data[2]; 114 115 if (buf_size == rawsize) { 116 int linesize = FFALIGN(s->width,2) * 2; 117 y_plane += frame->linesize[0] * s->height; 118 for (stream_ptr = 0; stream_ptr < rawsize; stream_ptr += linesize) { 119 y_plane -= frame->linesize[0]; 120 memcpy(y_plane, buf+stream_ptr, linesize); 121 } 122 } else { 123 124 /* iterate through each line in the height */ 125 for (y_ptr = 0, u_ptr = 0, v_ptr = 0; 126 y_ptr < (s->height * frame->linesize[0]); 127 y_ptr += frame->linesize[0] - s->width, 128 u_ptr += frame->linesize[1] - s->width / 4, 129 v_ptr += frame->linesize[2] - s->width / 4) { 130 131 /* reset predictors */ 132 cur_byte = buf[stream_ptr++]; 133 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0; 134 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4; 135 136 cur_byte = buf[stream_ptr++]; 137 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0; 138 y_pred += y_table[cur_byte & 0x0F]; 139 y_plane[y_ptr++] = y_pred; 140 141 cur_byte = buf[stream_ptr++]; 142 y_pred += y_table[cur_byte & 0x0F]; 143 y_plane[y_ptr++] = y_pred; 144 y_pred += y_table[(cur_byte & 0xF0) >> 4]; 145 y_plane[y_ptr++] = y_pred; 146 147 /* iterate through the remaining pixel groups (4 pixels/group) */ 148 pixel_groups = s->width / 4 - 1; 149 while (pixel_groups--) { 150 151 cur_byte = buf[stream_ptr++]; 152 u_pred += u_table[(cur_byte & 0xF0) >> 4]; 153 u_plane[u_ptr++] = u_pred; 154 y_pred += y_table[cur_byte & 0x0F]; 155 y_plane[y_ptr++] = y_pred; 156 157 cur_byte = buf[stream_ptr++]; 158 v_pred += v_table[(cur_byte & 0xF0) >> 4]; 159 v_plane[v_ptr++] = v_pred; 160 y_pred += y_table[cur_byte & 0x0F]; 161 y_plane[y_ptr++] = y_pred; 162 163 cur_byte = buf[stream_ptr++]; 164 y_pred += y_table[cur_byte & 0x0F]; 165 y_plane[y_ptr++] = y_pred; 166 y_pred += y_table[(cur_byte & 0xF0) >> 4]; 167 y_plane[y_ptr++] = y_pred; 168 169 } 170 } 171 } 172 173 *got_frame = 1; 174 175 return buf_size; 176} 177 178#if CONFIG_AURA_DECODER 179AVCodec ff_aura_decoder = { 180 .name = "aura", 181 .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"), 182 .type = AVMEDIA_TYPE_VIDEO, 183 .id = AV_CODEC_ID_AURA, 184 .priv_data_size = sizeof(CyuvDecodeContext), 185 .init = cyuv_decode_init, 186 .decode = cyuv_decode_frame, 187 .capabilities = CODEC_CAP_DR1, 188}; 189#endif 190 191#if CONFIG_CYUV_DECODER 192AVCodec ff_cyuv_decoder = { 193 .name = "cyuv", 194 .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"), 195 .type = AVMEDIA_TYPE_VIDEO, 196 .id = AV_CODEC_ID_CYUV, 197 .priv_data_size = sizeof(CyuvDecodeContext), 198 .init = cyuv_decode_init, 199 .decode = cyuv_decode_frame, 200 .capabilities = CODEC_CAP_DR1, 201}; 202#endif 203