3 * Copyright (c) 2005 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
25 * Intel Indeo 2 decoder.
27 #define ALT_BITSTREAM_READER_LE
29 #include "bitstream.h"
30 #include "indeo2data.h"
32 typedef struct Ir2Context{
33 AVCodecContext *avctx;
39 #define CODE_VLC_BITS 14
42 /* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */
43 static inline int ir2_get_code(GetBitContext *gb)
45 return get_vlc2(gb, ir2_vlc.table, CODE_VLC_BITS, 1) + 1;
48 static int ir2_decode_plane(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
60 /* first line contain absolute values, other lines contain deltas */
62 c = ir2_get_code(&ctx->gb);
63 if(c >= 0x80) { /* we have a run */
67 for (i = 0; i < c * 2; i++)
69 } else { /* copy two values from table */
70 dst[out++] = table[c * 2];
71 dst[out++] = table[(c * 2) + 1];
76 for (j = 1; j < height; j++){
79 c = ir2_get_code(&ctx->gb);
80 if(c >= 0x80) { /* we have a skip */
84 for (i = 0; i < c * 2; i++) {
85 dst[out] = dst[out - stride];
88 } else { /* add two deltas from table */
89 t = dst[out - stride] + (table[c * 2] - 128);
93 t = dst[out - stride] + (table[(c * 2) + 1] - 128);
104 static int ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
105 const uint8_t *table)
115 for (j = 0; j < height; j++){
118 c = ir2_get_code(&ctx->gb);
119 if(c >= 0x80) { /* we have a skip */
122 } else { /* add two deltas from table */
123 t = dst[out] + (((table[c * 2] - 128)*3) >> 2);
127 t = dst[out] + (((table[(c * 2) + 1] - 128)*3) >> 2);
138 static int ir2_decode_frame(AVCodecContext *avctx,
139 void *data, int *data_size,
140 uint8_t *buf, int buf_size)
142 Ir2Context * const s = avctx->priv_data;
143 AVFrame *picture = data;
144 AVFrame * const p= (AVFrame*)&s->picture;
148 avctx->release_buffer(avctx, p);
151 p->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
152 if (avctx->reget_buffer(avctx, p)) {
153 av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
157 s->decode_delta = buf[18];
159 /* decide whether frame uses deltas or not */
160 #ifndef ALT_BITSTREAM_READER_LE
161 for (i = 0; i < buf_size; i++)
162 buf[i] = ff_reverse[buf[i]];
164 start = 48; /* hardcoded for now */
166 init_get_bits(&s->gb, buf + start, buf_size - start);
168 if (s->decode_delta) { /* intraframe */
169 ir2_decode_plane(s, avctx->width, avctx->height,
170 s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
171 /* swapped U and V */
172 ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
173 s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
174 ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
175 s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
176 } else { /* interframe */
177 ir2_decode_plane_inter(s, avctx->width, avctx->height,
178 s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
179 /* swapped U and V */
180 ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
181 s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
182 ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
183 s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
186 *picture= *(AVFrame*)&s->picture;
187 *data_size = sizeof(AVPicture);
192 static int ir2_decode_init(AVCodecContext *avctx){
193 Ir2Context * const ic = avctx->priv_data;
197 avctx->pix_fmt= PIX_FMT_YUV410P;
200 init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
201 &ir2_codes[0][1], 4, 2,
202 #ifdef ALT_BITSTREAM_READER_LE
203 &ir2_codes[0][0], 4, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
205 &ir2_codes[0][0], 4, 2, INIT_VLC_USE_STATIC);
211 AVCodec indeo2_decoder = {