libavcodec/ptx.c
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00001 /*
00002  * V.Flash PTX (.ptx) image decoder
00003  * Copyright (c) 2007 Ivo van Poorten
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavutil/intreadwrite.h"
00023 #include "libavutil/imgutils.h"
00024 #include "avcodec.h"
00025 
00026 typedef struct PTXContext {
00027     AVFrame picture;
00028 } PTXContext;
00029 
00030 static av_cold int ptx_init(AVCodecContext *avctx) {
00031     PTXContext *s = avctx->priv_data;
00032 
00033     avcodec_get_frame_defaults(&s->picture);
00034     avctx->coded_frame= &s->picture;
00035 
00036     return 0;
00037 }
00038 
00039 static int ptx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
00040                             AVPacket *avpkt) {
00041     const uint8_t *buf = avpkt->data;
00042     const uint8_t *buf_end = avpkt->data + avpkt->size;
00043     PTXContext * const s = avctx->priv_data;
00044     AVFrame *picture = data;
00045     AVFrame * const p = &s->picture;
00046     unsigned int offset, w, h, y, stride, bytes_per_pixel;
00047     uint8_t *ptr;
00048 
00049     if (buf_end - buf < 14)
00050         return AVERROR_INVALIDDATA;
00051     offset          = AV_RL16(buf);
00052     w               = AV_RL16(buf+8);
00053     h               = AV_RL16(buf+10);
00054     bytes_per_pixel = AV_RL16(buf+12) >> 3;
00055 
00056     if (bytes_per_pixel != 2) {
00057         av_log_ask_for_sample(avctx, "Image format is not RGB15.\n");
00058         return -1;
00059     }
00060 
00061     avctx->pix_fmt = PIX_FMT_RGB555;
00062 
00063     if (buf_end - buf < offset)
00064         return AVERROR_INVALIDDATA;
00065     if (offset != 0x2c)
00066         av_log_ask_for_sample(avctx, "offset != 0x2c\n");
00067 
00068     buf += offset;
00069 
00070     if (p->data[0])
00071         avctx->release_buffer(avctx, p);
00072 
00073     if (av_image_check_size(w, h, 0, avctx))
00074         return -1;
00075     if (w != avctx->width || h != avctx->height)
00076         avcodec_set_dimensions(avctx, w, h);
00077     if (avctx->get_buffer(avctx, p) < 0) {
00078         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00079         return -1;
00080     }
00081 
00082     p->pict_type = AV_PICTURE_TYPE_I;
00083 
00084     ptr    = p->data[0];
00085     stride = p->linesize[0];
00086 
00087     for (y = 0; y < h && buf_end - buf >= w * bytes_per_pixel; y++) {
00088 #if HAVE_BIGENDIAN
00089         unsigned int x;
00090         for (x=0; x<w*bytes_per_pixel; x+=bytes_per_pixel)
00091             AV_WN16(ptr+x, AV_RL16(buf+x));
00092 #else
00093         memcpy(ptr, buf, w*bytes_per_pixel);
00094 #endif
00095         ptr += stride;
00096         buf += w*bytes_per_pixel;
00097     }
00098 
00099     *picture = s->picture;
00100     *data_size = sizeof(AVPicture);
00101 
00102     if (y < h) {
00103         av_log(avctx, AV_LOG_WARNING, "incomplete packet\n");
00104         return avpkt->size;
00105     }
00106 
00107     return offset + w*h*bytes_per_pixel;
00108 }
00109 
00110 static av_cold int ptx_end(AVCodecContext *avctx) {
00111     PTXContext *s = avctx->priv_data;
00112 
00113     if(s->picture.data[0])
00114         avctx->release_buffer(avctx, &s->picture);
00115 
00116     return 0;
00117 }
00118 
00119 AVCodec ff_ptx_decoder = {
00120     .name           = "ptx",
00121     .type           = AVMEDIA_TYPE_VIDEO,
00122     .id             = CODEC_ID_PTX,
00123     .priv_data_size = sizeof(PTXContext),
00124     .init           = ptx_init,
00125     .close          = ptx_end,
00126     .decode         = ptx_decode_frame,
00127     .capabilities   = CODEC_CAP_DR1,
00128     .long_name = NULL_IF_CONFIG_SMALL("V.Flash PTX image"),
00129 };