/*
  * Megalux Frame demuxer
  * Copyright (c) 2010 Peter Ross <pross@xvid.org>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file
  * Megalux Frame demuxer
  */
 

 #include "libavcodec/raw.h"

 #include "libavutil/imgutils.h"

 #include "libavutil/intreadwrite.h"
 #include "avformat.h"
 

 static const PixelFormatTag frm_pix_fmt_tags[] = {

     { AV_PIX_FMT_RGB555, 1 },

     { AV_PIX_FMT_RGB0,   2 },

     { AV_PIX_FMT_RGB24,  3 },
     { AV_PIX_FMT_BGR0,   4 },

     { AV_PIX_FMT_BGRA,   5 },

     { AV_PIX_FMT_NONE,   0 },

 };
 
 typedef struct {
     int count;
 } FrmContext;
 
 static int frm_read_probe(AVProbeData *p)
 {
     if (p->buf_size > 8 &&
         p->buf[0] == 'F' && p->buf[1] == 'R' && p->buf[2] == 'M' &&
         AV_RL16(&p->buf[4]) && AV_RL16(&p->buf[6]))

         return AVPROBE_SCORE_MAX / 4;

     return 0;
 }
 
 static int frm_read_header(AVFormatContext *avctx)
 {
     AVIOContext *pb = avctx->pb;
     AVStream *st = avformat_new_stream(avctx, 0);
     if (!st)
         return AVERROR(ENOMEM);
 

     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
     st->codecpar->codec_id   = AV_CODEC_ID_RAWVIDEO;

     avio_skip(pb, 3);
 

     st->codecpar->format    = avpriv_find_pix_fmt(frm_pix_fmt_tags, avio_r8(pb));
     if (!st->codecpar->format)

         return AVERROR_INVALIDDATA;
 

     st->codecpar->codec_tag  = 0;
     st->codecpar->width      = avio_rl16(pb);
     st->codecpar->height     = avio_rl16(pb);

     return 0;
 }
 
 static int frm_read_packet(AVFormatContext *avctx, AVPacket *pkt)
 {
     FrmContext *s = avctx->priv_data;

     AVCodecParameters *par = avctx->streams[0]->codecpar;

     int packet_size, ret;
 
     if (s->count)
         return AVERROR_EOF;
 

     packet_size = av_image_get_buffer_size(par->format, par->width, par->height, 1);

     if (packet_size < 0)
         return AVERROR_INVALIDDATA;
 
     ret = av_get_packet(avctx->pb, pkt, packet_size);
     if (ret < 0)
         return ret;
 

     if (par->format == AV_PIX_FMT_BGRA) {

         int i;
         for (i = 3; i + 1 <= pkt->size; i += 4)
             pkt->data[i] = 0xFF - pkt->data[i];
     }
 

     pkt->stream_index = 0;
     s->count++;
 
     return 0;
 }
 
 AVInputFormat ff_frm_demuxer = {
     .name           = "frm",
     .priv_data_size = sizeof(FrmContext),
     .long_name      = NULL_IF_CONFIG_SMALL("Megalux Frame"),
     .read_probe     = frm_read_probe,
     .read_header    = frm_read_header,
     .read_packet    = frm_read_packet,
 };