FFmpeg: libavcodec/indeo2.c Source File

00001 /*
00002  * Intel Indeo 2 codec
00003  * Copyright (c) 2005 Konstantin Shishkov
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00026 #define ALT_BITSTREAM_READER_LE
00027 #include "avcodec.h"
00028 #include "get_bits.h"
00029 #include "indeo2data.h"
00030 #include "libavutil/common.h"
00031 
00032 typedef struct Ir2Context{
00033     AVCodecContext *avctx;
00034     AVFrame picture;
00035     GetBitContext gb;
00036     int decode_delta;
00037 } Ir2Context;
00038 
00039 #define CODE_VLC_BITS 14
00040 static VLC ir2_vlc;
00041 
00042 /* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */
00043 static inline int ir2_get_code(GetBitContext *gb)
00044 {
00045     return get_vlc2(gb, ir2_vlc.table, CODE_VLC_BITS, 1) + 1;
00046 }
00047 
00048 static int ir2_decode_plane(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
00049                              const uint8_t *table)
00050 {
00051     int i;
00052     int j;
00053     int out = 0;
00054     int c;
00055     int t;
00056 
00057     if(width&1)
00058         return -1;
00059 
00060     /* first line contain absolute values, other lines contain deltas */
00061     while (out < width){
00062         c = ir2_get_code(&ctx->gb);
00063         if(c >= 0x80) { /* we have a run */
00064             c -= 0x7F;
00065             if(out + c*2 > width)
00066                 return -1;
00067             for (i = 0; i < c * 2; i++)
00068                 dst[out++] = 0x80;
00069         } else { /* copy two values from table */
00070             dst[out++] = table[c * 2];
00071             dst[out++] = table[(c * 2) + 1];
00072         }
00073     }
00074     dst += stride;
00075 
00076     for (j = 1; j < height; j++){
00077         out = 0;
00078         while (out < width){
00079             c = ir2_get_code(&ctx->gb);
00080             if(c >= 0x80) { /* we have a skip */
00081                 c -= 0x7F;
00082                 if(out + c*2 > width)
00083                     return -1;
00084                 for (i = 0; i < c * 2; i++) {
00085                     dst[out] = dst[out - stride];
00086                     out++;
00087                 }
00088             } else { /* add two deltas from table */
00089                 t = dst[out - stride] + (table[c * 2] - 128);
00090                 t= av_clip_uint8(t);
00091                 dst[out] = t;
00092                 out++;
00093                 t = dst[out - stride] + (table[(c * 2) + 1] - 128);
00094                 t= av_clip_uint8(t);
00095                 dst[out] = t;
00096                 out++;
00097             }
00098         }
00099         dst += stride;
00100     }
00101     return 0;
00102 }
00103 
00104 static int ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
00105                              const uint8_t *table)
00106 {
00107     int j;
00108     int out = 0;
00109     int c;
00110     int t;
00111 
00112     if(width&1)
00113         return -1;
00114 
00115     for (j = 0; j < height; j++){
00116         out = 0;
00117         while (out < width){
00118             c = ir2_get_code(&ctx->gb);
00119             if(c >= 0x80) { /* we have a skip */
00120                 c -= 0x7F;
00121                 out += c * 2;
00122             } else { /* add two deltas from table */
00123                 t = dst[out] + (((table[c * 2] - 128)*3) >> 2);
00124                 t= av_clip_uint8(t);
00125                 dst[out] = t;
00126                 out++;
00127                 t = dst[out] + (((table[(c * 2) + 1] - 128)*3) >> 2);
00128                 t= av_clip_uint8(t);
00129                 dst[out] = t;
00130                 out++;
00131             }
00132         }
00133         dst += stride;
00134     }
00135     return 0;
00136 }
00137 
00138 static int ir2_decode_frame(AVCodecContext *avctx,
00139                         void *data, int *data_size,
00140                         AVPacket *avpkt)
00141 {
00142     const uint8_t *buf = avpkt->data;
00143     int buf_size = avpkt->size;
00144     Ir2Context * const s = avctx->priv_data;
00145     AVFrame *picture = data;
00146     AVFrame * const p= (AVFrame*)&s->picture;
00147     int start;
00148 
00149     if(p->data[0])
00150         avctx->release_buffer(avctx, p);
00151 
00152     p->reference = 1;
00153     p->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
00154     if (avctx->reget_buffer(avctx, p)) {
00155         av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
00156         return -1;
00157     }
00158 
00159     start = 48; /* hardcoded for now */
00160 
00161     if (start >= buf_size) {
00162         av_log(s->avctx, AV_LOG_ERROR, "input buffer size too small (%d)\n", buf_size);
00163         return AVERROR_INVALIDDATA;
00164     }
00165 
00166     s->decode_delta = buf[18];
00167 
00168     /* decide whether frame uses deltas or not */
00169 #ifndef ALT_BITSTREAM_READER_LE
00170     for (i = 0; i < buf_size; i++)
00171         buf[i] = av_reverse[buf[i]];
00172 #endif
00173 
00174     init_get_bits(&s->gb, buf + start, (buf_size - start) * 8);
00175 
00176     if (s->decode_delta) { /* intraframe */
00177         ir2_decode_plane(s, avctx->width, avctx->height,
00178                          s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
00179         /* swapped U and V */
00180         ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
00181                          s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
00182         ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
00183                          s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
00184     } else { /* interframe */
00185         ir2_decode_plane_inter(s, avctx->width, avctx->height,
00186                          s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
00187         /* swapped U and V */
00188         ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
00189                          s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
00190         ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
00191                          s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
00192     }
00193 
00194     *picture= *(AVFrame*)&s->picture;
00195     *data_size = sizeof(AVPicture);
00196 
00197     return buf_size;
00198 }
00199 
00200 static av_cold int ir2_decode_init(AVCodecContext *avctx){
00201     Ir2Context * const ic = avctx->priv_data;
00202     static VLC_TYPE vlc_tables[1 << CODE_VLC_BITS][2];
00203 
00204     ic->avctx = avctx;
00205 
00206     avctx->pix_fmt= PIX_FMT_YUV410P;
00207 
00208     ir2_vlc.table = vlc_tables;
00209     ir2_vlc.table_allocated = 1 << CODE_VLC_BITS;
00210 #ifdef ALT_BITSTREAM_READER_LE
00211         init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
00212                  &ir2_codes[0][1], 4, 2,
00213                  &ir2_codes[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
00214 #else
00215         init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
00216                  &ir2_codes[0][1], 4, 2,
00217                  &ir2_codes[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
00218 #endif
00219 
00220     return 0;
00221 }
00222 
00223 static av_cold int ir2_decode_end(AVCodecContext *avctx){
00224     Ir2Context * const ic = avctx->priv_data;
00225     AVFrame *pic = &ic->picture;
00226 
00227     if (pic->data[0])
00228         avctx->release_buffer(avctx, pic);
00229 
00230     return 0;
00231 }
00232 
00233 AVCodec indeo2_decoder = {
00234     "indeo2",
00235     AVMEDIA_TYPE_VIDEO,
00236     CODEC_ID_INDEO2,
00237     sizeof(Ir2Context),
00238     ir2_decode_init,
00239     NULL,
00240     ir2_decode_end,
00241     ir2_decode_frame,
00242     CODEC_CAP_DR1,
00243     .long_name = NULL_IF_CONFIG_SMALL("Intel Indeo 2"),
00244 };