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 */
55 return AVERROR_INVALIDDATA;
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;
89 if (avctx->codec_id == AV_CODEC_ID_AURA) {
93 /* sanity check the buffer size: A buffer has 3x16-bytes tables
94 * followed by (height) lines each with 3 bytes to represent groups
95 * of 4 pixels. Thus, the total size of the buffer ought to be:
96 * (3 * 16) + height * (width * 3 / 4) */
97 if (buf_size == 48 + s->height * (s->width * 3 / 4)) {
98 avctx->pix_fmt = AV_PIX_FMT_YUV411P;
99 } else if(buf_size == rawsize ) {
100 avctx->pix_fmt = AV_PIX_FMT_UYVY422;
102 av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
103 buf_size, 48 + s->height * (s->width * 3 / 4));
104 return AVERROR_INVALIDDATA;
107 /* pixel data starts 48 bytes in, after 3x16-byte tables */
110 if (s->frame.data[0])
111 avctx->release_buffer(avctx, &s->frame);
113 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
114 s->frame.reference = 0;
115 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
116 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
120 y_plane = s->frame.data[0];
121 u_plane = s->frame.data[1];
122 v_plane = s->frame.data[2];
124 if (buf_size == rawsize) {
125 int linesize = FFALIGN(s->width,2) * 2;
126 y_plane += s->frame.linesize[0] * s->height;
127 for (stream_ptr = 0; stream_ptr < rawsize; stream_ptr += linesize) {
128 y_plane -= s->frame.linesize[0];
129 memcpy(y_plane, buf+stream_ptr, linesize);
133 /* iterate through each line in the height */
134 for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
135 y_ptr < (s->height * s->frame.linesize[0]);
136 y_ptr += s->frame.linesize[0] - s->width,
137 u_ptr += s->frame.linesize[1] - s->width / 4,
138 v_ptr += s->frame.linesize[2] - s->width / 4) {
140 /* reset predictors */
141 cur_byte = buf[stream_ptr++];
142 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
143 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
145 cur_byte = buf[stream_ptr++];
146 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
147 y_pred += y_table[cur_byte & 0x0F];
148 y_plane[y_ptr++] = y_pred;
150 cur_byte = buf[stream_ptr++];
151 y_pred += y_table[cur_byte & 0x0F];
152 y_plane[y_ptr++] = y_pred;
153 y_pred += y_table[(cur_byte & 0xF0) >> 4];
154 y_plane[y_ptr++] = y_pred;
156 /* iterate through the remaining pixel groups (4 pixels/group) */
157 pixel_groups = s->width / 4 - 1;
158 while (pixel_groups--) {
160 cur_byte = buf[stream_ptr++];
161 u_pred += u_table[(cur_byte & 0xF0) >> 4];
162 u_plane[u_ptr++] = u_pred;
163 y_pred += y_table[cur_byte & 0x0F];
164 y_plane[y_ptr++] = y_pred;
166 cur_byte = buf[stream_ptr++];
167 v_pred += v_table[(cur_byte & 0xF0) >> 4];
168 v_plane[v_ptr++] = v_pred;
169 y_pred += y_table[cur_byte & 0x0F];
170 y_plane[y_ptr++] = y_pred;
172 cur_byte = buf[stream_ptr++];
173 y_pred += y_table[cur_byte & 0x0F];
174 y_plane[y_ptr++] = y_pred;
175 y_pred += y_table[(cur_byte & 0xF0) >> 4];
176 y_plane[y_ptr++] = y_pred;
183 *(AVFrame*)data= s->frame;
188 static av_cold int cyuv_decode_end(AVCodecContext *avctx)
190 CyuvDecodeContext *s = avctx->priv_data;
192 if (s->frame.data[0])
193 avctx->release_buffer(avctx, &s->frame);
198 #if CONFIG_AURA_DECODER
199 AVCodec ff_aura_decoder = {
201 .type = AVMEDIA_TYPE_VIDEO,
202 .id = AV_CODEC_ID_AURA,
203 .priv_data_size = sizeof(CyuvDecodeContext),
204 .init = cyuv_decode_init,
205 .close = cyuv_decode_end,
206 .decode = cyuv_decode_frame,
207 .capabilities = CODEC_CAP_DR1,
208 .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
212 #if CONFIG_CYUV_DECODER
213 AVCodec ff_cyuv_decoder = {
215 .type = AVMEDIA_TYPE_VIDEO,
216 .id = AV_CODEC_ID_CYUV,
217 .priv_data_size = sizeof(CyuvDecodeContext),
218 .init = cyuv_decode_init,
219 .close = cyuv_decode_end,
220 .decode = cyuv_decode_frame,
221 .capabilities = CODEC_CAP_DR1,
222 .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),