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 Libav.
11 * Libav 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 * Libav 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 Libav; 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.
37 #include "libavutil/internal.h"
40 typedef struct CyuvDecodeContext {
41 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 */
53 return AVERROR_INVALIDDATA;
54 s->height = avctx->height;
55 avctx->pix_fmt = AV_PIX_FMT_YUV411P;
60 static int cyuv_decode_frame(AVCodecContext *avctx,
61 void *data, int *got_frame,
64 const uint8_t *buf = avpkt->data;
65 int buf_size = avpkt->size;
66 CyuvDecodeContext *s=avctx->priv_data;
67 AVFrame *frame = 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;
87 if (avctx->codec_id == AV_CODEC_ID_AURA) {
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 av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
97 buf_size, 48 + s->height * (s->width * 3 / 4));
98 return AVERROR_INVALIDDATA;
101 /* pixel data starts 48 bytes in, after 3x16-byte tables */
104 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
105 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
109 y_plane = frame->data[0];
110 u_plane = frame->data[1];
111 v_plane = 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 * frame->linesize[0]);
116 y_ptr += frame->linesize[0] - s->width,
117 u_ptr += frame->linesize[1] - s->width / 4,
118 v_ptr += 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;
166 #if CONFIG_AURA_DECODER
167 AVCodec ff_aura_decoder = {
169 .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
170 .type = AVMEDIA_TYPE_VIDEO,
171 .id = AV_CODEC_ID_AURA,
172 .priv_data_size = sizeof(CyuvDecodeContext),
173 .init = cyuv_decode_init,
174 .decode = cyuv_decode_frame,
175 .capabilities = CODEC_CAP_DR1,
179 #if CONFIG_CYUV_DECODER
180 AVCodec ff_cyuv_decoder = {
182 .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),
183 .type = AVMEDIA_TYPE_VIDEO,
184 .id = AV_CODEC_ID_CYUV,
185 .priv_data_size = sizeof(CyuvDecodeContext),
186 .init = cyuv_decode_init,
187 .decode = cyuv_decode_frame,
188 .capabilities = CODEC_CAP_DR1,