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 libavcodec/indeo2.c
24 * Intel Indeo 2 decoder.
25 */
26#define ALT_BITSTREAM_READER_LE
27#include "avcodec.h"
28#include "bitstream.h"
29#include "indeo2data.h"
30
31typedef struct Ir2Context{
32    AVCodecContext *avctx;
33    AVFrame picture;
34    GetBitContext gb;
35    int decode_delta;
36} Ir2Context;
37
38#define CODE_VLC_BITS 14
39static VLC ir2_vlc;
40
41/* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */
42static inline int ir2_get_code(GetBitContext *gb)
43{
44    return get_vlc2(gb, ir2_vlc.table, CODE_VLC_BITS, 1) + 1;
45}
46
47static int ir2_decode_plane(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
48                             const uint8_t *table)
49{
50    int i;
51    int j;
52    int out = 0;
53    int c;
54    int t;
55
56    if(width&1)
57        return -1;
58
59    /* first line contain absolute values, other lines contain deltas */
60    while (out < width){
61        c = ir2_get_code(&ctx->gb);
62        if(c >= 0x80) { /* we have a run */
63            c -= 0x7F;
64            if(out + c*2 > width)
65                return -1;
66            for (i = 0; i < c * 2; i++)
67                dst[out++] = 0x80;
68        } else { /* copy two values from table */
69            dst[out++] = table[c * 2];
70            dst[out++] = table[(c * 2) + 1];
71        }
72    }
73    dst += stride;
74
75    for (j = 1; j < height; j++){
76        out = 0;
77        while (out < width){
78            c = ir2_get_code(&ctx->gb);
79            if(c >= 0x80) { /* we have a skip */
80                c -= 0x7F;
81                if(out + c*2 > width)
82                    return -1;
83                for (i = 0; i < c * 2; i++) {
84                    dst[out] = dst[out - stride];
85                    out++;
86                }
87            } else { /* add two deltas from table */
88                t = dst[out - stride] + (table[c * 2] - 128);
89                t= av_clip_uint8(t);
90                dst[out] = t;
91                out++;
92                t = dst[out - stride] + (table[(c * 2) + 1] - 128);
93                t= av_clip_uint8(t);
94                dst[out] = t;
95                out++;
96            }
97        }
98        dst += stride;
99    }
100    return 0;
101}
102
103static int ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
104                             const uint8_t *table)
105{
106    int j;
107    int out = 0;
108    int c;
109    int t;
110
111    if(width&1)
112        return -1;
113
114    for (j = 0; j < height; j++){
115        out = 0;
116        while (out < width){
117            c = ir2_get_code(&ctx->gb);
118            if(c >= 0x80) { /* we have a skip */
119                c -= 0x7F;
120                out += c * 2;
121            } else { /* add two deltas from table */
122                t = dst[out] + (((table[c * 2] - 128)*3) >> 2);
123                t= av_clip_uint8(t);
124                dst[out] = t;
125                out++;
126                t = dst[out] + (((table[(c * 2) + 1] - 128)*3) >> 2);
127                t= av_clip_uint8(t);
128                dst[out] = t;
129                out++;
130            }
131        }
132        dst += stride;
133    }
134    return 0;
135}
136
137static int ir2_decode_frame(AVCodecContext *avctx,
138                        void *data, int *data_size,
139                        const uint8_t *buf, int buf_size)
140{
141    Ir2Context * const s = avctx->priv_data;
142    AVFrame *picture = data;
143    AVFrame * const p= (AVFrame*)&s->picture;
144    int start;
145
146    if(p->data[0])
147        avctx->release_buffer(avctx, p);
148
149    p->reference = 1;
150    p->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
151    if (avctx->reget_buffer(avctx, p)) {
152        av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
153        return -1;
154    }
155
156    s->decode_delta = buf[18];
157
158    /* decide whether frame uses deltas or not */
159#ifndef ALT_BITSTREAM_READER_LE
160    for (i = 0; i < buf_size; i++)
161        buf[i] = ff_reverse[buf[i]];
162#endif
163    start = 48; /* hardcoded for now */
164
165    init_get_bits(&s->gb, buf + start, buf_size - start);
166
167    if (s->decode_delta) { /* intraframe */
168        ir2_decode_plane(s, avctx->width, avctx->height,
169                         s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
170        /* swapped U and V */
171        ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
172                         s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
173        ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
174                         s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
175    } else { /* interframe */
176        ir2_decode_plane_inter(s, avctx->width, avctx->height,
177                         s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
178        /* swapped U and V */
179        ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
180                         s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
181        ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
182                         s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
183    }
184
185    *picture= *(AVFrame*)&s->picture;
186    *data_size = sizeof(AVPicture);
187
188    return buf_size;
189}
190
191static av_cold int ir2_decode_init(AVCodecContext *avctx){
192    Ir2Context * const ic = avctx->priv_data;
193
194    ic->avctx = avctx;
195
196    avctx->pix_fmt= PIX_FMT_YUV410P;
197
198    if (!ir2_vlc.table)
199#ifdef ALT_BITSTREAM_READER_LE
200        init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
201                 &ir2_codes[0][1], 4, 2,
202                 &ir2_codes[0][0], 4, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
203#else
204        init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
205                 &ir2_codes[0][1], 4, 2,
206                 &ir2_codes[0][0], 4, 2, INIT_VLC_USE_STATIC);
207#endif
208
209    return 0;
210}
211
212AVCodec indeo2_decoder = {
213    "indeo2",
214    CODEC_TYPE_VIDEO,
215    CODEC_ID_INDEO2,
216    sizeof(Ir2Context),
217    ir2_decode_init,
218    NULL,
219    NULL,
220    ir2_decode_frame,
221    CODEC_CAP_DR1,
222    .long_name = NULL_IF_CONFIG_SMALL("Intel Indeo 2"),
223};
224