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.
38 #include "libavutil/internal.h"
41 typedef struct CyuvDecodeContext {
42 AVCodecContext *avctx;
47 static av_cold int cyuv_decode_init(AVCodecContext *avctx)
49 CyuvDecodeContext *s = avctx->priv_data;
52 s->width = avctx->width;
53 /* width needs to be divisible by 4 for this codec to work */
55 return AVERROR_INVALIDDATA;
56 s->height = avctx->height;
57 avctx->pix_fmt = AV_PIX_FMT_YUV411P;
62 static int cyuv_decode_frame(AVCodecContext *avctx,
63 void *data, int *got_frame,
66 const uint8_t *buf = avpkt->data;
67 int buf_size = avpkt->size;
68 CyuvDecodeContext *s=avctx->priv_data;
70 unsigned char *y_plane;
71 unsigned char *u_plane;
72 unsigned char *v_plane;
77 /* prediction error tables (make it clear that they are signed values) */
78 const signed char *y_table = (const signed char*)buf + 0;
79 const signed char *u_table = (const signed char*)buf + 16;
80 const signed char *v_table = (const signed char*)buf + 32;
82 unsigned char y_pred, u_pred, v_pred;
84 unsigned char cur_byte;
88 if (avctx->codec_id == AV_CODEC_ID_AURA) {
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 av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
98 buf_size, 48 + s->height * (s->width * 3 / 4));
99 return AVERROR_INVALIDDATA;
102 /* pixel data starts 48 bytes in, after 3x16-byte tables */
105 if (s->frame.data[0])
106 avctx->release_buffer(avctx, &s->frame);
108 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
109 s->frame.reference = 0;
110 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
111 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
115 y_plane = s->frame.data[0];
116 u_plane = s->frame.data[1];
117 v_plane = s->frame.data[2];
119 /* iterate through each line in the height */
120 for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
121 y_ptr < (s->height * s->frame.linesize[0]);
122 y_ptr += s->frame.linesize[0] - s->width,
123 u_ptr += s->frame.linesize[1] - s->width / 4,
124 v_ptr += s->frame.linesize[2] - s->width / 4) {
126 /* reset predictors */
127 cur_byte = buf[stream_ptr++];
128 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
129 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
131 cur_byte = buf[stream_ptr++];
132 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
133 y_pred += y_table[cur_byte & 0x0F];
134 y_plane[y_ptr++] = y_pred;
136 cur_byte = buf[stream_ptr++];
137 y_pred += y_table[cur_byte & 0x0F];
138 y_plane[y_ptr++] = y_pred;
139 y_pred += y_table[(cur_byte & 0xF0) >> 4];
140 y_plane[y_ptr++] = y_pred;
142 /* iterate through the remaining pixel groups (4 pixels/group) */
143 pixel_groups = s->width / 4 - 1;
144 while (pixel_groups--) {
146 cur_byte = buf[stream_ptr++];
147 u_pred += u_table[(cur_byte & 0xF0) >> 4];
148 u_plane[u_ptr++] = u_pred;
149 y_pred += y_table[cur_byte & 0x0F];
150 y_plane[y_ptr++] = y_pred;
152 cur_byte = buf[stream_ptr++];
153 v_pred += v_table[(cur_byte & 0xF0) >> 4];
154 v_plane[v_ptr++] = v_pred;
155 y_pred += y_table[cur_byte & 0x0F];
156 y_plane[y_ptr++] = y_pred;
158 cur_byte = buf[stream_ptr++];
159 y_pred += y_table[cur_byte & 0x0F];
160 y_plane[y_ptr++] = y_pred;
161 y_pred += y_table[(cur_byte & 0xF0) >> 4];
162 y_plane[y_ptr++] = y_pred;
168 *(AVFrame*)data= s->frame;
173 static av_cold int cyuv_decode_end(AVCodecContext *avctx)
175 CyuvDecodeContext *s = avctx->priv_data;
177 if (s->frame.data[0])
178 avctx->release_buffer(avctx, &s->frame);
183 #if CONFIG_AURA_DECODER
184 AVCodec ff_aura_decoder = {
186 .type = AVMEDIA_TYPE_VIDEO,
187 .id = AV_CODEC_ID_AURA,
188 .priv_data_size = sizeof(CyuvDecodeContext),
189 .init = cyuv_decode_init,
190 .close = cyuv_decode_end,
191 .decode = cyuv_decode_frame,
192 .capabilities = CODEC_CAP_DR1,
193 .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
197 #if CONFIG_CYUV_DECODER
198 AVCodec ff_cyuv_decoder = {
200 .type = AVMEDIA_TYPE_VIDEO,
201 .id = AV_CODEC_ID_CYUV,
202 .priv_data_size = sizeof(CyuvDecodeContext),
203 .init = cyuv_decode_init,
204 .close = cyuv_decode_end,
205 .decode = cyuv_decode_frame,
206 .capabilities = CODEC_CAP_DR1,
207 .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),