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.
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 */
56 s->height = avctx->height;
57 avcodec_get_frame_defaults(&s->frame);
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;
86 int rawsize = s->height * FFALIGN(s->width,2) * 2;
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 avctx->pix_fmt = AV_PIX_FMT_YUV411P;
98 } else if(buf_size == rawsize ) {
99 avctx->pix_fmt = AV_PIX_FMT_UYVY422;
101 av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
102 buf_size, 48 + s->height * (s->width * 3 / 4));
106 /* pixel data starts 48 bytes in, after 3x16-byte tables */
109 if (s->frame.data[0])
110 avctx->release_buffer(avctx, &s->frame);
112 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
113 s->frame.reference = 0;
114 if (ff_get_buffer(avctx, &s->frame) < 0) {
115 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
119 y_plane = s->frame.data[0];
120 u_plane = s->frame.data[1];
121 v_plane = s->frame.data[2];
123 if (buf_size == rawsize) {
124 int linesize = FFALIGN(s->width,2) * 2;
125 y_plane += s->frame.linesize[0] * s->height;
126 for (stream_ptr = 0; stream_ptr < rawsize; stream_ptr += linesize) {
127 y_plane -= s->frame.linesize[0];
128 memcpy(y_plane, buf+stream_ptr, linesize);
132 /* iterate through each line in the height */
133 for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
134 y_ptr < (s->height * s->frame.linesize[0]);
135 y_ptr += s->frame.linesize[0] - s->width,
136 u_ptr += s->frame.linesize[1] - s->width / 4,
137 v_ptr += s->frame.linesize[2] - s->width / 4) {
139 /* reset predictors */
140 cur_byte = buf[stream_ptr++];
141 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
142 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
144 cur_byte = buf[stream_ptr++];
145 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
146 y_pred += y_table[cur_byte & 0x0F];
147 y_plane[y_ptr++] = y_pred;
149 cur_byte = buf[stream_ptr++];
150 y_pred += y_table[cur_byte & 0x0F];
151 y_plane[y_ptr++] = y_pred;
152 y_pred += y_table[(cur_byte & 0xF0) >> 4];
153 y_plane[y_ptr++] = y_pred;
155 /* iterate through the remaining pixel groups (4 pixels/group) */
156 pixel_groups = s->width / 4 - 1;
157 while (pixel_groups--) {
159 cur_byte = buf[stream_ptr++];
160 u_pred += u_table[(cur_byte & 0xF0) >> 4];
161 u_plane[u_ptr++] = u_pred;
162 y_pred += y_table[cur_byte & 0x0F];
163 y_plane[y_ptr++] = y_pred;
165 cur_byte = buf[stream_ptr++];
166 v_pred += v_table[(cur_byte & 0xF0) >> 4];
167 v_plane[v_ptr++] = v_pred;
168 y_pred += y_table[cur_byte & 0x0F];
169 y_plane[y_ptr++] = y_pred;
171 cur_byte = buf[stream_ptr++];
172 y_pred += y_table[cur_byte & 0x0F];
173 y_plane[y_ptr++] = y_pred;
174 y_pred += y_table[(cur_byte & 0xF0) >> 4];
175 y_plane[y_ptr++] = y_pred;
182 *(AVFrame*)data= s->frame;
187 static av_cold int cyuv_decode_end(AVCodecContext *avctx)
189 CyuvDecodeContext *s = avctx->priv_data;
191 if (s->frame.data[0])
192 avctx->release_buffer(avctx, &s->frame);
197 #if CONFIG_AURA_DECODER
198 AVCodec ff_aura_decoder = {
200 .type = AVMEDIA_TYPE_VIDEO,
201 .id = AV_CODEC_ID_AURA,
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("Auravision AURA"),
211 #if CONFIG_CYUV_DECODER
212 AVCodec ff_cyuv_decoder = {
214 .type = AVMEDIA_TYPE_VIDEO,
215 .id = AV_CODEC_ID_CYUV,
216 .priv_data_size = sizeof(CyuvDecodeContext),
217 .init = cyuv_decode_init,
218 .close = cyuv_decode_end,
219 .decode = cyuv_decode_frame,
220 .capabilities = CODEC_CAP_DR1,
221 .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),