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 "dsputil.h"
37
38
39typedef struct CyuvDecodeContext {
40    AVCodecContext *avctx;
41    int width, height;
42    AVFrame frame;
43} CyuvDecodeContext;
44
45static 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 -1;
54    s->height = avctx->height;
55    avctx->pix_fmt = PIX_FMT_YUV411P;
56
57    return 0;
58}
59
60static int cyuv_decode_frame(AVCodecContext *avctx,
61                             void *data, int *data_size,
62                             AVPacket *avpkt)
63{
64    const uint8_t *buf = avpkt->data;
65    int buf_size = avpkt->size;
66    CyuvDecodeContext *s=avctx->priv_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
85    if (avctx->codec_id == CODEC_ID_AURA) {
86        y_table = u_table;
87        u_table = v_table;
88    }
89    /* sanity check the buffer size: A buffer has 3x16-bytes tables
90     * followed by (height) lines each with 3 bytes to represent groups
91     * of 4 pixels. Thus, the total size of the buffer ought to be:
92     *    (3 * 16) + height * (width * 3 / 4) */
93    if (buf_size != 48 + s->height * (s->width * 3 / 4)) {
94        av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
95               buf_size, 48 + s->height * (s->width * 3 / 4));
96        return -1;
97    }
98
99    /* pixel data starts 48 bytes in, after 3x16-byte tables */
100    stream_ptr = 48;
101
102    if (s->frame.data[0])
103        avctx->release_buffer(avctx, &s->frame);
104
105    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
106    s->frame.reference = 0;
107    if (avctx->get_buffer(avctx, &s->frame) < 0) {
108        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
109        return -1;
110    }
111
112    y_plane = s->frame.data[0];
113    u_plane = s->frame.data[1];
114    v_plane = s->frame.data[2];
115
116    /* iterate through each line in the height */
117    for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
118         y_ptr < (s->height * s->frame.linesize[0]);
119         y_ptr += s->frame.linesize[0] - s->width,
120         u_ptr += s->frame.linesize[1] - s->width / 4,
121         v_ptr += s->frame.linesize[2] - s->width / 4) {
122
123        /* reset predictors */
124        cur_byte = buf[stream_ptr++];
125        u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
126        y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
127
128        cur_byte = buf[stream_ptr++];
129        v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
130        y_pred += y_table[cur_byte & 0x0F];
131        y_plane[y_ptr++] = y_pred;
132
133        cur_byte = buf[stream_ptr++];
134        y_pred += y_table[cur_byte & 0x0F];
135        y_plane[y_ptr++] = y_pred;
136        y_pred += y_table[(cur_byte & 0xF0) >> 4];
137        y_plane[y_ptr++] = y_pred;
138
139        /* iterate through the remaining pixel groups (4 pixels/group) */
140        pixel_groups = s->width / 4 - 1;
141        while (pixel_groups--) {
142
143            cur_byte = buf[stream_ptr++];
144            u_pred += u_table[(cur_byte & 0xF0) >> 4];
145            u_plane[u_ptr++] = u_pred;
146            y_pred += y_table[cur_byte & 0x0F];
147            y_plane[y_ptr++] = y_pred;
148
149            cur_byte = buf[stream_ptr++];
150            v_pred += v_table[(cur_byte & 0xF0) >> 4];
151            v_plane[v_ptr++] = v_pred;
152            y_pred += y_table[cur_byte & 0x0F];
153            y_plane[y_ptr++] = y_pred;
154
155            cur_byte = buf[stream_ptr++];
156            y_pred += y_table[cur_byte & 0x0F];
157            y_plane[y_ptr++] = y_pred;
158            y_pred += y_table[(cur_byte & 0xF0) >> 4];
159            y_plane[y_ptr++] = y_pred;
160
161        }
162    }
163
164    *data_size=sizeof(AVFrame);
165    *(AVFrame*)data= s->frame;
166
167    return buf_size;
168}
169
170static av_cold int cyuv_decode_end(AVCodecContext *avctx)
171{
172    CyuvDecodeContext *s = avctx->priv_data;
173
174    if (s->frame.data[0])
175        avctx->release_buffer(avctx, &s->frame);
176
177    return 0;
178}
179
180#if CONFIG_AURA_DECODER
181AVCodec aura_decoder = {
182    "aura",
183    AVMEDIA_TYPE_VIDEO,
184    CODEC_ID_AURA,
185    sizeof(CyuvDecodeContext),
186    cyuv_decode_init,
187    NULL,
188    cyuv_decode_end,
189    cyuv_decode_frame,
190    CODEC_CAP_DR1,
191    NULL,
192    .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
193};
194#endif
195
196#if CONFIG_CYUV_DECODER
197AVCodec cyuv_decoder = {
198    "cyuv",
199    AVMEDIA_TYPE_VIDEO,
200    CODEC_ID_CYUV,
201    sizeof(CyuvDecodeContext),
202    cyuv_decode_init,
203    NULL,
204    cyuv_decode_end,
205    cyuv_decode_frame,
206    CODEC_CAP_DR1,
207    NULL,
208    .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),
209};
210#endif
211