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libavcodec/rawdec.c

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00001 /*
00002  * Raw Video Decoder
00003  * Copyright (c) 2001 Fabrice Bellard
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 "raw.h"
00029 
00030 typedef struct RawVideoContext {
00031     unsigned char * buffer;  /* block of memory for holding one frame */
00032     int             length;  /* number of bytes in buffer */
00033     int flip;
00034     AVFrame pic;             
00035 } RawVideoContext;
00036 
00037 static const PixelFormatTag pixelFormatBpsAVI[] = {
00038     { PIX_FMT_PAL8,    4 },
00039     { PIX_FMT_PAL8,    8 },
00040     { PIX_FMT_RGB555, 15 },
00041     { PIX_FMT_RGB555, 16 },
00042     { PIX_FMT_BGR24,  24 },
00043     { PIX_FMT_RGB32,  32 },
00044     { PIX_FMT_NONE, 0 },
00045 };
00046 
00047 static const PixelFormatTag pixelFormatBpsMOV[] = {
00048     /* FIXME fix swscaler to support those */
00049     /* http://developer.apple.com/documentation/QuickTime/QTFF/QTFFChap3/chapter_4_section_2.html */
00050     { PIX_FMT_PAL8,      4 },
00051     { PIX_FMT_PAL8,      8 },
00052     { PIX_FMT_BGR555,   16 },
00053     { PIX_FMT_RGB24,    24 },
00054     { PIX_FMT_BGR32_1,  32 },
00055     { PIX_FMT_NONE, 0 },
00056 };
00057 
00058 static enum PixelFormat findPixelFormat(const PixelFormatTag *tags, unsigned int fourcc)
00059 {
00060     while (tags->pix_fmt >= 0) {
00061         if (tags->fourcc == fourcc)
00062             return tags->pix_fmt;
00063         tags++;
00064     }
00065     return PIX_FMT_YUV420P;
00066 }
00067 
00068 static av_cold int raw_init_decoder(AVCodecContext *avctx)
00069 {
00070     RawVideoContext *context = avctx->priv_data;
00071 
00072     if (avctx->codec_tag == MKTAG('r','a','w',' '))
00073         avctx->pix_fmt = findPixelFormat(pixelFormatBpsMOV, avctx->bits_per_coded_sample);
00074     else if (avctx->codec_tag)
00075         avctx->pix_fmt = findPixelFormat(ff_raw_pixelFormatTags, avctx->codec_tag);
00076     else if (avctx->bits_per_coded_sample)
00077         avctx->pix_fmt = findPixelFormat(pixelFormatBpsAVI, avctx->bits_per_coded_sample);
00078 
00079     context->length = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);
00080     context->buffer = av_malloc(context->length);
00081     context->pic.pict_type = FF_I_TYPE;
00082     context->pic.key_frame = 1;
00083 
00084     avctx->coded_frame= &context->pic;
00085 
00086     if (!context->buffer)
00087         return -1;
00088 
00089     if(avctx->extradata_size >= 9 && !memcmp(avctx->extradata + avctx->extradata_size - 9, "BottomUp", 9))
00090         context->flip=1;
00091 
00092     return 0;
00093 }
00094 
00095 static void flip(AVCodecContext *avctx, AVPicture * picture){
00096     picture->data[0] += picture->linesize[0] * (avctx->height-1);
00097     picture->linesize[0] *= -1;
00098 }
00099 
00100 static int raw_decode(AVCodecContext *avctx,
00101                             void *data, int *data_size,
00102                             const uint8_t *buf, int buf_size)
00103 {
00104     RawVideoContext *context = avctx->priv_data;
00105 
00106     AVFrame * frame = (AVFrame *) data;
00107     AVPicture * picture = (AVPicture *) data;
00108 
00109     frame->interlaced_frame = avctx->coded_frame->interlaced_frame;
00110     frame->top_field_first = avctx->coded_frame->top_field_first;
00111 
00112     //4bpp raw in avi and mov (yes this is ugly ...)
00113     if(avctx->bits_per_coded_sample == 4 && avctx->pix_fmt==PIX_FMT_PAL8 &&
00114        (!avctx->codec_tag || avctx->codec_tag == MKTAG('r','a','w',' '))){
00115         int i;
00116         for(i=256*2; i+1 < context->length>>1; i++){
00117             context->buffer[2*i+0]= buf[i-256*2]>>4;
00118             context->buffer[2*i+1]= buf[i-256*2]&15;
00119         }
00120         buf= context->buffer + 256*4;
00121         buf_size= context->length - 256*4;
00122     }
00123 
00124     if(buf_size < context->length - (avctx->pix_fmt==PIX_FMT_PAL8 ? 256*4 : 0))
00125         return -1;
00126 
00127     avpicture_fill(picture, buf, avctx->pix_fmt, avctx->width, avctx->height);
00128     if(avctx->pix_fmt==PIX_FMT_PAL8 && buf_size < context->length){
00129         frame->data[1]= context->buffer;
00130     }
00131     if (avctx->palctrl && avctx->palctrl->palette_changed) {
00132         memcpy(frame->data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
00133         avctx->palctrl->palette_changed = 0;
00134     }
00135 
00136     if(context->flip)
00137         flip(avctx, picture);
00138 
00139     if (avctx->codec_tag == MKTAG('Y', 'V', '1', '2'))
00140     {
00141         // swap fields
00142         unsigned char *tmp = picture->data[1];
00143         picture->data[1] = picture->data[2];
00144         picture->data[2] = tmp;
00145     }
00146 
00147     *data_size = sizeof(AVPicture);
00148     return buf_size;
00149 }
00150 
00151 static av_cold int raw_close_decoder(AVCodecContext *avctx)
00152 {
00153     RawVideoContext *context = avctx->priv_data;
00154 
00155     av_freep(&context->buffer);
00156     return 0;
00157 }
00158 
00159 AVCodec rawvideo_decoder = {
00160     "rawvideo",
00161     CODEC_TYPE_VIDEO,
00162     CODEC_ID_RAWVIDEO,
00163     sizeof(RawVideoContext),
00164     raw_init_decoder,
00165     NULL,
00166     raw_close_decoder,
00167     raw_decode,
00168     .long_name = NULL_IF_CONFIG_SMALL("raw video"),
00169 };

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