libavformat/bmv.c

   1 /*
   2  * Discworld II BMV demuxer
   3  * Copyright (c) 2011 Konstantin Shishkov.
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/channel_layout.h"
  23 #include "avformat.h"
  24 #include "internal.h"
  25
  26 enum BMVFlags {
  27     BMV_NOP = 0,
  28     BMV_END,
  29     BMV_DELTA,
  30     BMV_INTRA,
  31
  32     BMV_AUDIO   = 0x20,
  33 };
  34
  35 typedef struct BMVContext {
  36     uint8_t *packet;
  37     int      size;
  38     int      get_next;
  39     int64_t  audio_pos;
  40 } BMVContext;
  41
  42 static int bmv_read_header(AVFormatContext *s)
  43 {
  44     AVStream *st, *ast;
  45     BMVContext *c = s->priv_data;
  46
  47     st = avformat_new_stream(s, 0);
  48     if (!st)
  49         return AVERROR(ENOMEM);
  50     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
  51     st->codec->codec_id   = AV_CODEC_ID_BMV_VIDEO;
  52     st->codec->width      = 640;
  53     st->codec->height     = 429;
  54     st->codec->pix_fmt    = AV_PIX_FMT_PAL8;
  55     avpriv_set_pts_info(st, 16, 1, 12);
  56     ast = avformat_new_stream(s, 0);
  57     if (!ast)
  58         return AVERROR(ENOMEM);
  59     ast->codec->codec_type      = AVMEDIA_TYPE_AUDIO;
  60     ast->codec->codec_id        = AV_CODEC_ID_BMV_AUDIO;
  61     ast->codec->channels        = 2;
  62     ast->codec->channel_layout  = AV_CH_LAYOUT_STEREO;
  63     ast->codec->sample_rate     = 22050;
  64     avpriv_set_pts_info(ast, 16, 1, 22050);
  65
  66     c->get_next  = 1;
  67     c->audio_pos = 0;
  68     return 0;
  69 }
  70
  71 static int bmv_read_packet(AVFormatContext *s, AVPacket *pkt)
  72 {
  73     BMVContext *c = s->priv_data;
  74     int type;
  75     void *tmp;
  76
  77     while (c->get_next) {
  78         if (s->pb->eof_reached)
  79             return AVERROR_EOF;
  80         type = avio_r8(s->pb);
  81         if (type == BMV_NOP)
  82             continue;
  83         if (type == BMV_END)
  84             return AVERROR_EOF;
  85         c->size = avio_rl24(s->pb);
  86         if (!c->size)
  87             return AVERROR_INVALIDDATA;
  88         tmp = av_realloc(c->packet, c->size + 1);
  89         if (!tmp)
  90             return AVERROR(ENOMEM);
  91         c->packet = tmp;
  92         c->packet[0] = type;
  93         if (avio_read(s->pb, c->packet + 1, c->size) != c->size)
  94             return AVERROR(EIO);
  95         if (type & BMV_AUDIO) {
  96             int audio_size = c->packet[1] * 65 + 1;
  97             if (audio_size >= c->size) {
  98                 av_log(s, AV_LOG_ERROR, "Reported audio size %d is bigger than packet size (%d)\n",
  99                        audio_size, c->size);
 100                 return AVERROR_INVALIDDATA;
 101             }
 102             if (av_new_packet(pkt, audio_size) < 0)
 103                 return AVERROR(ENOMEM);
 104             memcpy(pkt->data, c->packet + 1, pkt->size);
 105             pkt->stream_index = 1;
 106             pkt->pts          = c->audio_pos;
 107             pkt->duration     = c->packet[1] * 32;
 108             c->audio_pos += pkt->duration;
 109             c->get_next   = 0;
 110             return pkt->size;
 111         } else
 112             break;
 113     }
 114     if (av_new_packet(pkt, c->size + 1) < 0)
 115         return AVERROR(ENOMEM);
 116     pkt->stream_index = 0;
 117     c->get_next = 1;
 118     memcpy(pkt->data, c->packet, pkt->size);
 119     return pkt->size;
 120 }
 121
 122 static int bmv_read_close(AVFormatContext *s)
 123 {
 124     BMVContext *c = s->priv_data;
 125
 126     av_freep(&c->packet);
 127
 128     return 0;
 129 }
 130
 131 AVInputFormat ff_bmv_demuxer = {
 132     .name           = "bmv",
 133     .long_name      = NULL_IF_CONFIG_SMALL("Discworld II BMV"),
 134     .priv_data_size = sizeof(BMVContext),
 135     .read_header    = bmv_read_header,
 136     .read_packet    = bmv_read_packet,
 137     .read_close     = bmv_read_close,
 138     .extensions     = "bmv",
 139 };