libavformat/frmdec.c

   1 /*
   2  * Megalux Frame demuxer
   3  * Copyright (c) 2010 Peter Ross <pross@xvid.org>
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * Megalux Frame demuxer
  25  */
  26
  27 #include "libavutil/imgutils.h"
  28 #include "libavutil/intreadwrite.h"
  29 #include "avformat.h"
  30 #include "demux.h"
  31
  32 static const enum AVPixelFormat frm_pix_fmt_tags[] = {
  33     AV_PIX_FMT_RGB555,
  34     AV_PIX_FMT_RGB0,
  35     AV_PIX_FMT_RGB24,
  36     AV_PIX_FMT_BGR0,
  37     AV_PIX_FMT_BGRA,
  38 };
  39
  40 typedef struct {
  41     int count;
  42 } FrmContext;
  43
  44 static int frm_read_probe(const AVProbeData *p)
  45 {
  46     if (p->buf_size > 8 &&
  47         p->buf[0] == 'F' && p->buf[1] == 'R' && p->buf[2] == 'M' &&
  48         AV_RL16(&p->buf[4]) && AV_RL16(&p->buf[6]))
  49         return AVPROBE_SCORE_MAX / 4;
  50     return 0;
  51 }
  52
  53 static int frm_read_header(AVFormatContext *avctx)
  54 {
  55     AVIOContext *pb = avctx->pb;
  56     AVStream *st = avformat_new_stream(avctx, 0);
  57     unsigned idx;
  58
  59     if (!st)
  60         return AVERROR(ENOMEM);
  61
  62     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
  63     st->codecpar->codec_id   = AV_CODEC_ID_RAWVIDEO;
  64     avio_skip(pb, 3);
  65
  66     idx = avio_r8(pb) - 1;
  67     if (idx >= FF_ARRAY_ELEMS(frm_pix_fmt_tags))
  68         return AVERROR_INVALIDDATA;
  69     st->codecpar->format = frm_pix_fmt_tags[idx];
  70
  71     st->codecpar->codec_tag  = 0;
  72     st->codecpar->width      = avio_rl16(pb);
  73     st->codecpar->height     = avio_rl16(pb);
  74     return 0;
  75 }
  76
  77 static int frm_read_packet(AVFormatContext *avctx, AVPacket *pkt)
  78 {
  79     FrmContext *s = avctx->priv_data;
  80     AVCodecParameters *par = avctx->streams[0]->codecpar;
  81     int packet_size, ret;
  82
  83     if (s->count)
  84         return AVERROR_EOF;
  85
  86     packet_size = av_image_get_buffer_size(par->format, par->width, par->height, 1);
  87     if (packet_size < 0)
  88         return AVERROR_INVALIDDATA;
  89
  90     ret = av_get_packet(avctx->pb, pkt, packet_size);
  91     if (ret < 0)
  92         return ret;
  93
  94     if (par->format == AV_PIX_FMT_BGRA) {
  95         int i;
  96         for (i = 3; i + 1 <= pkt->size; i += 4)
  97             pkt->data[i] = 0xFF - pkt->data[i];
  98     }
  99
 100     pkt->stream_index = 0;
 101     s->count++;
 102
 103     return 0;
 104 }
 105
 106 const FFInputFormat ff_frm_demuxer = {
 107     .p.name         = "frm",
 108     .p.long_name    = NULL_IF_CONFIG_SMALL("Megalux Frame"),
 109     .priv_data_size = sizeof(FrmContext),
 110     .read_probe     = frm_read_probe,
 111     .read_header    = frm_read_header,
 112     .read_packet    = frm_read_packet,
 113 };