release/src/router/ffmpeg/libavcodec/cyuv.c

   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 "dsputil.h"
  37
  38
  39 typedef struct CyuvDecodeContext {
  40     AVCodecContext *avctx;
  41     int width, height;
  42     AVFrame frame;
  43 } CyuvDecodeContext;
  44
  45 static 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 -1;
  54     s->height = avctx->height;
  55     avctx->pix_fmt = PIX_FMT_YUV411P;
  56
  57     return 0;
  58 }
  59
  60 static int cyuv_decode_frame(AVCodecContext *avctx,
  61                              void *data, int *data_size,
  62                              AVPacket *avpkt)
  63 {
  64     const uint8_t *buf = avpkt->data;
  65     int buf_size = avpkt->size;
  66     CyuvDecodeContext *s=avctx->priv_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
  85     if (avctx->codec_id == CODEC_ID_AURA) {
  86         y_table = u_table;
  87         u_table = v_table;
  88     }
  89     /* sanity check the buffer size: A buffer has 3x16-bytes tables
  90      * followed by (height) lines each with 3 bytes to represent groups
  91      * of 4 pixels. Thus, the total size of the buffer ought to be:
  92      *    (3 * 16) + height * (width * 3 / 4) */
  93     if (buf_size != 48 + s->height * (s->width * 3 / 4)) {
  94         av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
  95                buf_size, 48 + s->height * (s->width * 3 / 4));
  96         return -1;
  97     }
  98
  99     /* pixel data starts 48 bytes in, after 3x16-byte tables */
 100     stream_ptr = 48;
 101
 102     if (s->frame.data[0])
 103         avctx->release_buffer(avctx, &s->frame);
 104
 105     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
 106     s->frame.reference = 0;
 107     if (avctx->get_buffer(avctx, &s->frame) < 0) {
 108         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 109         return -1;
 110     }
 111
 112     y_plane = s->frame.data[0];
 113     u_plane = s->frame.data[1];
 114     v_plane = s->frame.data[2];
 115
 116     /* iterate through each line in the height */
 117     for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
 118          y_ptr < (s->height * s->frame.linesize[0]);
 119          y_ptr += s->frame.linesize[0] - s->width,
 120          u_ptr += s->frame.linesize[1] - s->width / 4,
 121          v_ptr += s->frame.linesize[2] - s->width / 4) {
 122
 123         /* reset predictors */
 124         cur_byte = buf[stream_ptr++];
 125         u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
 126         y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
 127
 128         cur_byte = buf[stream_ptr++];
 129         v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
 130         y_pred += y_table[cur_byte & 0x0F];
 131         y_plane[y_ptr++] = y_pred;
 132
 133         cur_byte = buf[stream_ptr++];
 134         y_pred += y_table[cur_byte & 0x0F];
 135         y_plane[y_ptr++] = y_pred;
 136         y_pred += y_table[(cur_byte & 0xF0) >> 4];
 137         y_plane[y_ptr++] = y_pred;
 138
 139         /* iterate through the remaining pixel groups (4 pixels/group) */
 140         pixel_groups = s->width / 4 - 1;
 141         while (pixel_groups--) {
 142
 143             cur_byte = buf[stream_ptr++];
 144             u_pred += u_table[(cur_byte & 0xF0) >> 4];
 145             u_plane[u_ptr++] = u_pred;
 146             y_pred += y_table[cur_byte & 0x0F];
 147             y_plane[y_ptr++] = y_pred;
 148
 149             cur_byte = buf[stream_ptr++];
 150             v_pred += v_table[(cur_byte & 0xF0) >> 4];
 151             v_plane[v_ptr++] = v_pred;
 152             y_pred += y_table[cur_byte & 0x0F];
 153             y_plane[y_ptr++] = y_pred;
 154
 155             cur_byte = buf[stream_ptr++];
 156             y_pred += y_table[cur_byte & 0x0F];
 157             y_plane[y_ptr++] = y_pred;
 158             y_pred += y_table[(cur_byte & 0xF0) >> 4];
 159             y_plane[y_ptr++] = y_pred;
 160
 161         }
 162     }
 163
 164     *data_size=sizeof(AVFrame);
 165     *(AVFrame*)data= s->frame;
 166
 167     return buf_size;
 168 }
 169
 170 static av_cold int cyuv_decode_end(AVCodecContext *avctx)
 171 {
 172     CyuvDecodeContext *s = avctx->priv_data;
 173
 174     if (s->frame.data[0])
 175         avctx->release_buffer(avctx, &s->frame);
 176
 177     return 0;
 178 }
 179
 180 #if CONFIG_AURA_DECODER
 181 AVCodec aura_decoder = {
 182     "aura",
 183     AVMEDIA_TYPE_VIDEO,
 184     CODEC_ID_AURA,
 185     sizeof(CyuvDecodeContext),
 186     cyuv_decode_init,
 187     NULL,
 188     cyuv_decode_end,
 189     cyuv_decode_frame,
 190     CODEC_CAP_DR1,
 191     NULL,
 192     .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
 193 };
 194 #endif
 195
 196 #if CONFIG_CYUV_DECODER
 197 AVCodec cyuv_decoder = {
 198     "cyuv",
 199     AVMEDIA_TYPE_VIDEO,
 200     CODEC_ID_CYUV,
 201     sizeof(CyuvDecodeContext),
 202     cyuv_decode_init,
 203     NULL,
 204     cyuv_decode_end,
 205     cyuv_decode_frame,
 206     CODEC_CAP_DR1,
 207     NULL,
 208     .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),
 209 };
 210 #endif