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
40typedef struct CyuvDecodeContext {
41    AVCodecContext *avctx;
42    int width, height;
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 AVERROR_INVALIDDATA;
54    s->height = avctx->height;
55
56    return 0;
57}
58
59static 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
179AVCodec 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   = CODEC_CAP_DR1,
188};
189#endif
190
191#if CONFIG_CYUV_DECODER
192AVCodec ff_cyuv_decoder = {
193    .name           = "cyuv",
194    .long_name      = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),
195    .type           = AVMEDIA_TYPE_VIDEO,
196    .id             = AV_CODEC_ID_CYUV,
197    .priv_data_size = sizeof(CyuvDecodeContext),
198    .init           = cyuv_decode_init,
199    .decode         = cyuv_decode_frame,
200    .capabilities   = CODEC_CAP_DR1,
201};
202#endif
203