1/*
2 * Intel Indeo 2 codec
3 * Copyright (c) 2005 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * Intel Indeo 2 decoder.
25 */
26#define ALT_BITSTREAM_READER_LE
27#include "avcodec.h"
28#include "get_bits.h"
29#include "indeo2data.h"
30#include "libavutil/common.h"
31
32typedef struct Ir2Context{
33    AVCodecContext *avctx;
34    AVFrame picture;
35    GetBitContext gb;
36    int decode_delta;
37} Ir2Context;
38
39#define CODE_VLC_BITS 14
40static VLC ir2_vlc;
41
42/* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */
43static inline int ir2_get_code(GetBitContext *gb)
44{
45    return get_vlc2(gb, ir2_vlc.table, CODE_VLC_BITS, 1) + 1;
46}
47
48static int ir2_decode_plane(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
49                             const uint8_t *table)
50{
51    int i;
52    int j;
53    int out = 0;
54    int c;
55    int t;
56
57    if(width&1)
58        return -1;
59
60    /* first line contain absolute values, other lines contain deltas */
61    while (out < width){
62        c = ir2_get_code(&ctx->gb);
63        if(c >= 0x80) { /* we have a run */
64            c -= 0x7F;
65            if(out + c*2 > width)
66                return -1;
67            for (i = 0; i < c * 2; i++)
68                dst[out++] = 0x80;
69        } else { /* copy two values from table */
70            dst[out++] = table[c * 2];
71            dst[out++] = table[(c * 2) + 1];
72        }
73    }
74    dst += stride;
75
76    for (j = 1; j < height; j++){
77        out = 0;
78        while (out < width){
79            c = ir2_get_code(&ctx->gb);
80            if(c >= 0x80) { /* we have a skip */
81                c -= 0x7F;
82                if(out + c*2 > width)
83                    return -1;
84                for (i = 0; i < c * 2; i++) {
85                    dst[out] = dst[out - stride];
86                    out++;
87                }
88            } else { /* add two deltas from table */
89                t = dst[out - stride] + (table[c * 2] - 128);
90                t= av_clip_uint8(t);
91                dst[out] = t;
92                out++;
93                t = dst[out - stride] + (table[(c * 2) + 1] - 128);
94                t= av_clip_uint8(t);
95                dst[out] = t;
96                out++;
97            }
98        }
99        dst += stride;
100    }
101    return 0;
102}
103
104static int ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
105                             const uint8_t *table)
106{
107    int j;
108    int out = 0;
109    int c;
110    int t;
111
112    if(width&1)
113        return -1;
114
115    for (j = 0; j < height; j++){
116        out = 0;
117        while (out < width){
118            c = ir2_get_code(&ctx->gb);
119            if(c >= 0x80) { /* we have a skip */
120                c -= 0x7F;
121                out += c * 2;
122            } else { /* add two deltas from table */
123                t = dst[out] + (((table[c * 2] - 128)*3) >> 2);
124                t= av_clip_uint8(t);
125                dst[out] = t;
126                out++;
127                t = dst[out] + (((table[(c * 2) + 1] - 128)*3) >> 2);
128                t= av_clip_uint8(t);
129                dst[out] = t;
130                out++;
131            }
132        }
133        dst += stride;
134    }
135    return 0;
136}
137
138static int ir2_decode_frame(AVCodecContext *avctx,
139                        void *data, int *data_size,
140                        AVPacket *avpkt)
141{
142    const uint8_t *buf = avpkt->data;
143    int buf_size = avpkt->size;
144    Ir2Context * const s = avctx->priv_data;
145    AVFrame *picture = data;
146    AVFrame * const p= (AVFrame*)&s->picture;
147    int start;
148
149    if(p->data[0])
150        avctx->release_buffer(avctx, p);
151
152    p->reference = 1;
153    p->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
154    if (avctx->reget_buffer(avctx, p)) {
155        av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
156        return -1;
157    }
158
159    s->decode_delta = buf[18];
160
161    /* decide whether frame uses deltas or not */
162#ifndef ALT_BITSTREAM_READER_LE
163    for (i = 0; i < buf_size; i++)
164        buf[i] = av_reverse[buf[i]];
165#endif
166    start = 48; /* hardcoded for now */
167
168    init_get_bits(&s->gb, buf + start, buf_size - start);
169
170    if (s->decode_delta) { /* intraframe */
171        ir2_decode_plane(s, avctx->width, avctx->height,
172                         s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
173        /* swapped U and V */
174        ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
175                         s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
176        ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
177                         s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
178    } else { /* interframe */
179        ir2_decode_plane_inter(s, avctx->width, avctx->height,
180                         s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
181        /* swapped U and V */
182        ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
183                         s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
184        ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
185                         s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
186    }
187
188    *picture= *(AVFrame*)&s->picture;
189    *data_size = sizeof(AVPicture);
190
191    return buf_size;
192}
193
194static av_cold int ir2_decode_init(AVCodecContext *avctx){
195    Ir2Context * const ic = avctx->priv_data;
196    static VLC_TYPE vlc_tables[1 << CODE_VLC_BITS][2];
197
198    ic->avctx = avctx;
199
200    avctx->pix_fmt= PIX_FMT_YUV410P;
201
202    ir2_vlc.table = vlc_tables;
203    ir2_vlc.table_allocated = 1 << CODE_VLC_BITS;
204#ifdef ALT_BITSTREAM_READER_LE
205        init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
206                 &ir2_codes[0][1], 4, 2,
207                 &ir2_codes[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
208#else
209        init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
210                 &ir2_codes[0][1], 4, 2,
211                 &ir2_codes[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
212#endif
213
214    return 0;
215}
216
217static av_cold int ir2_decode_end(AVCodecContext *avctx){
218    Ir2Context * const ic = avctx->priv_data;
219    AVFrame *pic = &ic->picture;
220
221    if (pic->data[0])
222        avctx->release_buffer(avctx, pic);
223
224    return 0;
225}
226
227AVCodec indeo2_decoder = {
228    "indeo2",
229    AVMEDIA_TYPE_VIDEO,
230    CODEC_ID_INDEO2,
231    sizeof(Ir2Context),
232    ir2_decode_init,
233    NULL,
234    ir2_decode_end,
235    ir2_decode_frame,
236    CODEC_CAP_DR1,
237    .long_name = NULL_IF_CONFIG_SMALL("Intel Indeo 2"),
238};
239