1 /*
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
6 *
7 * Copyright (C) 2003 The FFmpeg project
8 *
9 * This file is part of FFmpeg.
10 *
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.
15 *
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.
20 *
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
24 */
25
26 /**
27 * @file
28 * Creative YUV (CYUV) Video Decoder.
29 */
30
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34
35 #include "avcodec.h"
36 #include "internal.h"
37 #include "libavutil/internal.h"
38
39
40 typedef struct CyuvDecodeContext {
41 AVCodecContext *avctx;
42 int width, height;
43 } CyuvDecodeContext;
44
cyuv_decode_init(AVCodecContext * avctx)45 static av_cold int cyuv_decode_init(AVCodecContext *avctx)
46 {
47 CyuvDecodeContext *s = avctx->priv_data;
48
49 s->avctx = avctx;
50 s->width = avctx->width;
51 /* width needs to be divisible by 4 for this codec to work */
52 if (s->width & 0x3)
53 return AVERROR_INVALIDDATA;
54 s->height = avctx->height;
55
56 return 0;
57 }
58
cyuv_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)59 static int cyuv_decode_frame(AVCodecContext *avctx,
60 void *data, int *got_frame,
61 AVPacket *avpkt)
62 {
63 const uint8_t *buf = avpkt->data;
64 int buf_size = avpkt->size;
65 CyuvDecodeContext *s=avctx->priv_data;
66 AVFrame *frame = data;
67
68 unsigned char *y_plane;
69 unsigned char *u_plane;
70 unsigned char *v_plane;
71 int y_ptr;
72 int u_ptr;
73 int v_ptr;
74
75 /* prediction error tables (make it clear that they are signed values) */
76 const signed char *y_table = (const signed char*)buf + 0;
77 const signed char *u_table = (const signed char*)buf + 16;
78 const signed char *v_table = (const signed char*)buf + 32;
79
80 unsigned char y_pred, u_pred, v_pred;
81 int stream_ptr;
82 unsigned char cur_byte;
83 int pixel_groups;
84 int rawsize = s->height * FFALIGN(s->width,2) * 2;
85 int ret;
86
87 if (avctx->codec_id == AV_CODEC_ID_AURA) {
88 y_table = u_table;
89 u_table = v_table;
90 }
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 avctx->pix_fmt = AV_PIX_FMT_YUV411P;
97 } else if(buf_size == rawsize ) {
98 avctx->pix_fmt = AV_PIX_FMT_UYVY422;
99 } else {
100 av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
101 buf_size, 48 + s->height * (s->width * 3 / 4));
102 return AVERROR_INVALIDDATA;
103 }
104
105 /* pixel data starts 48 bytes in, after 3x16-byte tables */
106 stream_ptr = 48;
107
108 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
109 return ret;
110
111 y_plane = frame->data[0];
112 u_plane = frame->data[1];
113 v_plane = frame->data[2];
114
115 if (buf_size == rawsize) {
116 int linesize = FFALIGN(s->width,2) * 2;
117 y_plane += frame->linesize[0] * s->height;
118 for (stream_ptr = 0; stream_ptr < rawsize; stream_ptr += linesize) {
119 y_plane -= frame->linesize[0];
120 memcpy(y_plane, buf+stream_ptr, linesize);
121 }
122 } else {
123
124 /* iterate through each line in the height */
125 for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
126 y_ptr < (s->height * frame->linesize[0]);
127 y_ptr += frame->linesize[0] - s->width,
128 u_ptr += frame->linesize[1] - s->width / 4,
129 v_ptr += frame->linesize[2] - s->width / 4) {
130
131 /* reset predictors */
132 cur_byte = buf[stream_ptr++];
133 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
134 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
135
136 cur_byte = buf[stream_ptr++];
137 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
138 y_pred += y_table[cur_byte & 0x0F];
139 y_plane[y_ptr++] = y_pred;
140
141 cur_byte = buf[stream_ptr++];
142 y_pred += y_table[cur_byte & 0x0F];
143 y_plane[y_ptr++] = y_pred;
144 y_pred += y_table[(cur_byte & 0xF0) >> 4];
145 y_plane[y_ptr++] = y_pred;
146
147 /* iterate through the remaining pixel groups (4 pixels/group) */
148 pixel_groups = s->width / 4 - 1;
149 while (pixel_groups--) {
150
151 cur_byte = buf[stream_ptr++];
152 u_pred += u_table[(cur_byte & 0xF0) >> 4];
153 u_plane[u_ptr++] = u_pred;
154 y_pred += y_table[cur_byte & 0x0F];
155 y_plane[y_ptr++] = y_pred;
156
157 cur_byte = buf[stream_ptr++];
158 v_pred += v_table[(cur_byte & 0xF0) >> 4];
159 v_plane[v_ptr++] = v_pred;
160 y_pred += y_table[cur_byte & 0x0F];
161 y_plane[y_ptr++] = y_pred;
162
163 cur_byte = buf[stream_ptr++];
164 y_pred += y_table[cur_byte & 0x0F];
165 y_plane[y_ptr++] = y_pred;
166 y_pred += y_table[(cur_byte & 0xF0) >> 4];
167 y_plane[y_ptr++] = y_pred;
168
169 }
170 }
171 }
172
173 *got_frame = 1;
174
175 return buf_size;
176 }
177
178 #if CONFIG_AURA_DECODER
179 AVCodec ff_aura_decoder = {
180 .name = "aura",
181 .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
182 .type = AVMEDIA_TYPE_VIDEO,
183 .id = AV_CODEC_ID_AURA,
184 .priv_data_size = sizeof(CyuvDecodeContext),
185 .init = cyuv_decode_init,
186 .decode = cyuv_decode_frame,
187 .capabilities = AV_CODEC_CAP_DR1,
188 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
189 };
190 #endif
191
192 #if CONFIG_CYUV_DECODER
193 AVCodec ff_cyuv_decoder = {
194 .name = "cyuv",
195 .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),
196 .type = AVMEDIA_TYPE_VIDEO,
197 .id = AV_CODEC_ID_CYUV,
198 .priv_data_size = sizeof(CyuvDecodeContext),
199 .init = cyuv_decode_init,
200 .decode = cyuv_decode_frame,
201 .capabilities = AV_CODEC_CAP_DR1,
202 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
203 };
204 #endif
205