3 * Copyright (C) 2003 the ffmpeg project
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Creative YUV (CYUV) Video Decoder
20 * by Mike Melanson (melanson@pcisys.net)
21 * based on "Creative YUV (CYUV) stream format for AVI":
22 * http://www.csse.monash.edu.au/~timf/videocodec/cyuv.txt
28 * Creative YUV (CYUV) Video Decoder.
39 #include "mpegvideo.h"
42 typedef struct CyuvDecodeContext {
43 AVCodecContext *avctx;
48 static int cyuv_decode_init(AVCodecContext *avctx)
50 CyuvDecodeContext *s = avctx->priv_data;
53 s->width = avctx->width;
54 s->height = avctx->height;
55 avctx->pix_fmt = PIX_FMT_YUV411P;
56 avctx->has_b_frames = 0;
61 static int cyuv_decode_frame(AVCodecContext *avctx,
62 void *data, int *data_size,
63 uint8_t *buf, int buf_size)
65 CyuvDecodeContext *s=avctx->priv_data;
67 unsigned char *y_plane;
68 unsigned char *u_plane;
69 unsigned char *v_plane;
74 /* prediction error tables (make it clear that they are signed values) */
75 signed char *y_table = buf + 0;
76 signed char *u_table = buf + 16;
77 signed char *v_table = buf + 32;
79 unsigned char y_pred, u_pred, v_pred;
81 unsigned char cur_byte;
86 /* sanity check the buffer size: A buffer has 3x16-bytes tables
87 * followed by (height) lines each with 3 bytes to represent groups
88 * of 4 pixels. Thus, the total size of the buffer ought to be:
89 * (3 * 16) + height * (width * 3 / 4) */
90 if (buf_size != 48 + s->height * (s->width * 3 / 4)) {
91 printf ("ffmpeg: cyuv: got a buffer with %d bytes when %d were expected\n",
93 48 + s->height * (s->width * 3 / 4));
97 /* pixel data starts 48 bytes in, after 3x16-byte tables */
101 avctx->release_buffer(avctx, &s->frame);
103 s->frame.reference = 0;
104 if(avctx->get_buffer(avctx, &s->frame) < 0) {
105 fprintf(stderr, "get_buffer() failed\n");
109 y_plane = s->frame.data[0];
110 u_plane = s->frame.data[1];
111 v_plane = s->frame.data[2];
113 /* iterate through each line in the height */
114 for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
115 y_ptr < (s->height * s->frame.linesize[0]);
116 y_ptr += s->frame.linesize[0] - s->width,
117 u_ptr += s->frame.linesize[1] - s->width / 4,
118 v_ptr += s->frame.linesize[2] - s->width / 4) {
120 /* reset predictors */
121 cur_byte = buf[stream_ptr++];
122 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
123 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
125 cur_byte = buf[stream_ptr++];
126 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
127 y_pred += y_table[cur_byte & 0x0F];
128 y_plane[y_ptr++] = y_pred;
130 cur_byte = buf[stream_ptr++];
131 y_pred += y_table[cur_byte & 0x0F];
132 y_plane[y_ptr++] = y_pred;
133 y_pred += y_table[(cur_byte & 0xF0) >> 4];
134 y_plane[y_ptr++] = y_pred;
136 /* iterate through the remaining pixel groups (4 pixels/group) */
137 pixel_groups = s->width / 4 - 1;
138 while (pixel_groups--) {
140 cur_byte = buf[stream_ptr++];
141 u_pred += u_table[(cur_byte & 0xF0) >> 4];
142 u_plane[u_ptr++] = u_pred;
143 y_pred += y_table[cur_byte & 0x0F];
144 y_plane[y_ptr++] = y_pred;
146 cur_byte = buf[stream_ptr++];
147 v_pred += v_table[(cur_byte & 0xF0) >> 4];
148 v_plane[v_ptr++] = v_pred;
149 y_pred += y_table[cur_byte & 0x0F];
150 y_plane[y_ptr++] = y_pred;
152 cur_byte = buf[stream_ptr++];
153 y_pred += y_table[cur_byte & 0x0F];
154 y_plane[y_ptr++] = y_pred;
155 y_pred += y_table[(cur_byte & 0xF0) >> 4];
156 y_plane[y_ptr++] = y_pred;
161 *data_size=sizeof(AVFrame);
162 *(AVFrame*)data= s->frame;
167 static int cyuv_decode_end(AVCodecContext *avctx)
169 /* CyuvDecodeContext *s = avctx->priv_data;*/
174 AVCodec cyuv_decoder = {
178 sizeof(CyuvDecodeContext),