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
7 * Copyright (C) 2003 the ffmpeg project
9 * This file is part of FFmpeg.
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.
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.
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
28 * Creative YUV (CYUV) Video Decoder.
39 typedef struct CyuvDecodeContext {
40 AVCodecContext *avctx;
45 static av_cold int cyuv_decode_init(AVCodecContext *avctx)
47 CyuvDecodeContext *s = avctx->priv_data;
50 s->width = avctx->width;
51 /* width needs to be divisible by 4 for this codec to work */
54 s->height = avctx->height;
55 avctx->pix_fmt = PIX_FMT_YUV411P;
56 avcodec_get_frame_defaults(&s->frame);
61 static int cyuv_decode_frame(AVCodecContext *avctx,
62 void *data, int *data_size,
65 const uint8_t *buf = avpkt->data;
66 int buf_size = avpkt->size;
67 CyuvDecodeContext *s=avctx->priv_data;
69 unsigned char *y_plane;
70 unsigned char *u_plane;
71 unsigned char *v_plane;
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;
81 unsigned char y_pred, u_pred, v_pred;
83 unsigned char cur_byte;
86 if (avctx->codec_id == AV_CODEC_ID_AURA) {
90 /* sanity check the buffer size: A buffer has 3x16-bytes tables
91 * followed by (height) lines each with 3 bytes to represent groups
92 * of 4 pixels. Thus, the total size of the buffer ought to be:
93 * (3 * 16) + height * (width * 3 / 4) */
94 if (buf_size != 48 + s->height * (s->width * 3 / 4)) {
95 av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
96 buf_size, 48 + s->height * (s->width * 3 / 4));
100 /* pixel data starts 48 bytes in, after 3x16-byte tables */
103 if (s->frame.data[0])
104 avctx->release_buffer(avctx, &s->frame);
106 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
107 s->frame.reference = 0;
108 if (avctx->get_buffer(avctx, &s->frame) < 0) {
109 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
113 y_plane = s->frame.data[0];
114 u_plane = s->frame.data[1];
115 v_plane = s->frame.data[2];
117 /* iterate through each line in the height */
118 for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
119 y_ptr < (s->height * s->frame.linesize[0]);
120 y_ptr += s->frame.linesize[0] - s->width,
121 u_ptr += s->frame.linesize[1] - s->width / 4,
122 v_ptr += s->frame.linesize[2] - s->width / 4) {
124 /* reset predictors */
125 cur_byte = buf[stream_ptr++];
126 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
127 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
129 cur_byte = buf[stream_ptr++];
130 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
131 y_pred += y_table[cur_byte & 0x0F];
132 y_plane[y_ptr++] = y_pred;
134 cur_byte = buf[stream_ptr++];
135 y_pred += y_table[cur_byte & 0x0F];
136 y_plane[y_ptr++] = y_pred;
137 y_pred += y_table[(cur_byte & 0xF0) >> 4];
138 y_plane[y_ptr++] = y_pred;
140 /* iterate through the remaining pixel groups (4 pixels/group) */
141 pixel_groups = s->width / 4 - 1;
142 while (pixel_groups--) {
144 cur_byte = buf[stream_ptr++];
145 u_pred += u_table[(cur_byte & 0xF0) >> 4];
146 u_plane[u_ptr++] = u_pred;
147 y_pred += y_table[cur_byte & 0x0F];
148 y_plane[y_ptr++] = y_pred;
150 cur_byte = buf[stream_ptr++];
151 v_pred += v_table[(cur_byte & 0xF0) >> 4];
152 v_plane[v_ptr++] = v_pred;
153 y_pred += y_table[cur_byte & 0x0F];
154 y_plane[y_ptr++] = y_pred;
156 cur_byte = buf[stream_ptr++];
157 y_pred += y_table[cur_byte & 0x0F];
158 y_plane[y_ptr++] = y_pred;
159 y_pred += y_table[(cur_byte & 0xF0) >> 4];
160 y_plane[y_ptr++] = y_pred;
165 *data_size=sizeof(AVFrame);
166 *(AVFrame*)data= s->frame;
171 static av_cold int cyuv_decode_end(AVCodecContext *avctx)
173 CyuvDecodeContext *s = avctx->priv_data;
175 if (s->frame.data[0])
176 avctx->release_buffer(avctx, &s->frame);
181 #if CONFIG_AURA_DECODER
182 AVCodec ff_aura_decoder = {
184 .type = AVMEDIA_TYPE_VIDEO,
185 .id = AV_CODEC_ID_AURA,
186 .priv_data_size = sizeof(CyuvDecodeContext),
187 .init = cyuv_decode_init,
188 .close = cyuv_decode_end,
189 .decode = cyuv_decode_frame,
190 .capabilities = CODEC_CAP_DR1,
191 .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
195 #if CONFIG_CYUV_DECODER
196 AVCodec ff_cyuv_decoder = {
198 .type = AVMEDIA_TYPE_VIDEO,
199 .id = AV_CODEC_ID_CYUV,
200 .priv_data_size = sizeof(CyuvDecodeContext),
201 .init = cyuv_decode_init,
202 .close = cyuv_decode_end,
203 .decode = cyuv_decode_frame,
204 .capabilities = CODEC_CAP_DR1,
205 .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),