FFmpeg: libavcodec/sp5xdec.c Source File

00001 /*
00002  * Sunplus JPEG decoder (SP5X)
00003  * Copyright (c) 2003 Alex Beregszaszi
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 
00027 #include "avcodec.h"
00028 #include "mjpeg.h"
00029 #include "mjpegdec.h"
00030 #include "sp5x.h"
00031 
00032 
00033 static int sp5x_decode_frame(AVCodecContext *avctx,
00034                               void *data, int *data_size,
00035                               AVPacket *avpkt)
00036 {
00037     const uint8_t *buf = avpkt->data;
00038     int buf_size = avpkt->size;
00039     AVPacket avpkt_recoded;
00040     const int qscale = 5;
00041     uint8_t *recoded;
00042     int i = 0, j = 0;
00043 
00044     if (!avctx->width || !avctx->height)
00045         return -1;
00046 
00047     recoded = av_mallocz(buf_size + 1024);
00048     if (!recoded)
00049         return -1;
00050 
00051     /* SOI */
00052     recoded[j++] = 0xFF;
00053     recoded[j++] = 0xD8;
00054 
00055     memcpy(recoded+j, &sp5x_data_dqt[0], sizeof(sp5x_data_dqt));
00056     memcpy(recoded+j+5, &sp5x_quant_table[qscale * 2], 64);
00057     memcpy(recoded+j+70, &sp5x_quant_table[(qscale * 2) + 1], 64);
00058     j += sizeof(sp5x_data_dqt);
00059 
00060     memcpy(recoded+j, &sp5x_data_dht[0], sizeof(sp5x_data_dht));
00061     j += sizeof(sp5x_data_dht);
00062 
00063     memcpy(recoded+j, &sp5x_data_sof[0], sizeof(sp5x_data_sof));
00064     AV_WB16(recoded+j+5, avctx->coded_height);
00065     AV_WB16(recoded+j+7, avctx->coded_width);
00066     j += sizeof(sp5x_data_sof);
00067 
00068     memcpy(recoded+j, &sp5x_data_sos[0], sizeof(sp5x_data_sos));
00069     j += sizeof(sp5x_data_sos);
00070 
00071     if(avctx->codec_id==CODEC_ID_AMV)
00072         for (i = 2; i < buf_size-2 && j < buf_size+1024-2; i++)
00073             recoded[j++] = buf[i];
00074     else
00075     for (i = 14; i < buf_size && j < buf_size+1024-2; i++)
00076     {
00077         recoded[j++] = buf[i];
00078         if (buf[i] == 0xff)
00079             recoded[j++] = 0;
00080     }
00081 
00082     /* EOI */
00083     recoded[j++] = 0xFF;
00084     recoded[j++] = 0xD9;
00085 
00086     av_init_packet(&avpkt_recoded);
00087     avpkt_recoded.data = recoded;
00088     avpkt_recoded.size = j;
00089     i = ff_mjpeg_decode_frame(avctx, data, data_size, &avpkt_recoded);
00090 
00091     av_free(recoded);
00092 
00093     return i;
00094 }
00095 
00096 AVCodec ff_sp5x_decoder = {
00097     "sp5x",
00098     AVMEDIA_TYPE_VIDEO,
00099     CODEC_ID_SP5X,
00100     sizeof(MJpegDecodeContext),
00101     ff_mjpeg_decode_init,
00102     NULL,
00103     ff_mjpeg_decode_end,
00104     sp5x_decode_frame,
00105     CODEC_CAP_DR1,
00106     NULL,
00107     .max_lowres = 3,
00108     .long_name = NULL_IF_CONFIG_SMALL("Sunplus JPEG (SP5X)"),
00109 };
00110 
00111 AVCodec ff_amv_decoder = {
00112     "amv",
00113     AVMEDIA_TYPE_VIDEO,
00114     CODEC_ID_AMV,
00115     sizeof(MJpegDecodeContext),
00116     ff_mjpeg_decode_init,
00117     NULL,
00118     ff_mjpeg_decode_end,
00119     sp5x_decode_frame,
00120     0,
00121     .long_name = NULL_IF_CONFIG_SMALL("AMV Video"),
00122 };