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 "config_components.h" 32 33#include <stdio.h> 34#include <stdlib.h> 35#include <string.h> 36 37#include "avcodec.h" 38#include "codec_internal.h" 39#include "internal.h" 40#include "libavutil/internal.h" 41 42 43typedef struct CyuvDecodeContext { 44 AVCodecContext *avctx; 45 int width, height; 46} CyuvDecodeContext; 47 48static av_cold int cyuv_decode_init(AVCodecContext *avctx) 49{ 50 CyuvDecodeContext *s = avctx->priv_data; 51 52 s->avctx = avctx; 53 s->width = avctx->width; 54 /* width needs to be divisible by 4 for this codec to work */ 55 if (s->width & 0x3) 56 return AVERROR_INVALIDDATA; 57 s->height = avctx->height; 58 59 return 0; 60} 61 62static int cyuv_decode_frame(AVCodecContext *avctx, AVFrame *frame, 63 int *got_frame, AVPacket *avpkt) 64{ 65 const uint8_t *buf = avpkt->data; 66 int buf_size = avpkt->size; 67 CyuvDecodeContext *s=avctx->priv_data; 68 69 unsigned char *y_plane; 70 unsigned char *u_plane; 71 unsigned char *v_plane; 72 int y_ptr; 73 int u_ptr; 74 int v_ptr; 75 76 /* prediction error tables (make it clear that they are signed values) */ 77 const signed char *y_table = (const signed char*)buf + 0; 78 const signed char *u_table = (const signed char*)buf + 16; 79 const signed char *v_table = (const signed char*)buf + 32; 80 81 unsigned char y_pred, u_pred, v_pred; 82 int stream_ptr; 83 unsigned char cur_byte; 84 int pixel_groups; 85 int rawsize = s->height * FFALIGN(s->width,2) * 2; 86 int ret; 87 88 if (avctx->codec_id == AV_CODEC_ID_AURA) { 89 y_table = u_table; 90 u_table = v_table; 91 } 92 /* sanity check the buffer size: A buffer has 3x16-bytes tables 93 * followed by (height) lines each with 3 bytes to represent groups 94 * of 4 pixels. Thus, the total size of the buffer ought to be: 95 * (3 * 16) + height * (width * 3 / 4) */ 96 if (buf_size == 48 + s->height * (s->width * 3 / 4)) { 97 avctx->pix_fmt = AV_PIX_FMT_YUV411P; 98 } else if(buf_size == rawsize ) { 99 avctx->pix_fmt = AV_PIX_FMT_UYVY422; 100 } else { 101 av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n", 102 buf_size, 48 + s->height * (s->width * 3 / 4)); 103 return AVERROR_INVALIDDATA; 104 } 105 106 /* pixel data starts 48 bytes in, after 3x16-byte tables */ 107 stream_ptr = 48; 108 109 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 110 return ret; 111 112 y_plane = frame->data[0]; 113 u_plane = frame->data[1]; 114 v_plane = frame->data[2]; 115 116 if (buf_size == rawsize) { 117 int linesize = FFALIGN(s->width,2) * 2; 118 y_plane += frame->linesize[0] * s->height; 119 for (stream_ptr = 0; stream_ptr < rawsize; stream_ptr += linesize) { 120 y_plane -= frame->linesize[0]; 121 memcpy(y_plane, buf+stream_ptr, linesize); 122 } 123 } else { 124 125 /* iterate through each line in the height */ 126 for (y_ptr = 0, u_ptr = 0, v_ptr = 0; 127 y_ptr < (s->height * frame->linesize[0]); 128 y_ptr += frame->linesize[0] - s->width, 129 u_ptr += frame->linesize[1] - s->width / 4, 130 v_ptr += frame->linesize[2] - s->width / 4) { 131 132 /* reset predictors */ 133 cur_byte = buf[stream_ptr++]; 134 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0; 135 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4; 136 137 cur_byte = buf[stream_ptr++]; 138 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0; 139 y_pred += y_table[cur_byte & 0x0F]; 140 y_plane[y_ptr++] = y_pred; 141 142 cur_byte = buf[stream_ptr++]; 143 y_pred += y_table[cur_byte & 0x0F]; 144 y_plane[y_ptr++] = y_pred; 145 y_pred += y_table[(cur_byte & 0xF0) >> 4]; 146 y_plane[y_ptr++] = y_pred; 147 148 /* iterate through the remaining pixel groups (4 pixels/group) */ 149 pixel_groups = s->width / 4 - 1; 150 while (pixel_groups--) { 151 152 cur_byte = buf[stream_ptr++]; 153 u_pred += u_table[(cur_byte & 0xF0) >> 4]; 154 u_plane[u_ptr++] = u_pred; 155 y_pred += y_table[cur_byte & 0x0F]; 156 y_plane[y_ptr++] = y_pred; 157 158 cur_byte = buf[stream_ptr++]; 159 v_pred += v_table[(cur_byte & 0xF0) >> 4]; 160 v_plane[v_ptr++] = v_pred; 161 y_pred += y_table[cur_byte & 0x0F]; 162 y_plane[y_ptr++] = y_pred; 163 164 cur_byte = buf[stream_ptr++]; 165 y_pred += y_table[cur_byte & 0x0F]; 166 y_plane[y_ptr++] = y_pred; 167 y_pred += y_table[(cur_byte & 0xF0) >> 4]; 168 y_plane[y_ptr++] = y_pred; 169 170 } 171 } 172 } 173 174 *got_frame = 1; 175 176 return buf_size; 177} 178 179#if CONFIG_AURA_DECODER 180const FFCodec ff_aura_decoder = { 181 .p.name = "aura", 182 .p.long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"), 183 .p.type = AVMEDIA_TYPE_VIDEO, 184 .p.id = AV_CODEC_ID_AURA, 185 .priv_data_size = sizeof(CyuvDecodeContext), 186 .init = cyuv_decode_init, 187 FF_CODEC_DECODE_CB(cyuv_decode_frame), 188 .p.capabilities = AV_CODEC_CAP_DR1, 189 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 190}; 191#endif 192 193#if CONFIG_CYUV_DECODER 194const FFCodec ff_cyuv_decoder = { 195 .p.name = "cyuv", 196 .p.long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"), 197 .p.type = AVMEDIA_TYPE_VIDEO, 198 .p.id = AV_CODEC_ID_CYUV, 199 .priv_data_size = sizeof(CyuvDecodeContext), 200 .init = cyuv_decode_init, 201 FF_CODEC_DECODE_CB(cyuv_decode_frame), 202 .p.capabilities = AV_CODEC_CAP_DR1, 203 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 204}; 205#endif 206