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libavformat/bmv.c

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00001 /*
00002  * Discworld II BMV demuxer
00003  * Copyright (c) 2011 Konstantin Shishkov.
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 "avformat.h"
00023 #include "internal.h"
00024 
00025 enum BMVFlags {
00026     BMV_NOP = 0,
00027     BMV_END,
00028     BMV_DELTA,
00029     BMV_INTRA,
00030 
00031     BMV_AUDIO   = 0x20,
00032 };
00033 
00034 typedef struct BMVContext {
00035     uint8_t *packet;
00036     int      size;
00037     int      get_next;
00038     int64_t  audio_pos;
00039 } BMVContext;
00040 
00041 static int bmv_read_header(AVFormatContext *s, AVFormatParameters *ap)
00042 {
00043     AVStream *st, *ast;
00044     BMVContext *c = s->priv_data;
00045 
00046     st = avformat_new_stream(s, 0);
00047     if (!st)
00048         return AVERROR(ENOMEM);
00049     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00050     st->codec->codec_id   = CODEC_ID_BMV_VIDEO;
00051     st->codec->width      = 640;
00052     st->codec->height     = 429;
00053     st->codec->pix_fmt    = PIX_FMT_PAL8;
00054     avpriv_set_pts_info(st, 16, 1, 12);
00055     ast = avformat_new_stream(s, 0);
00056     if (!ast)
00057         return AVERROR(ENOMEM);
00058     ast->codec->codec_type      = AVMEDIA_TYPE_AUDIO;
00059     ast->codec->codec_id        = CODEC_ID_BMV_AUDIO;
00060     ast->codec->channels        = 2;
00061     ast->codec->sample_rate     = 22050;
00062     avpriv_set_pts_info(ast, 16, 1, 22050);
00063 
00064     c->get_next  = 1;
00065     c->audio_pos = 0;
00066     return 0;
00067 }
00068 
00069 static int bmv_read_packet(AVFormatContext *s, AVPacket *pkt)
00070 {
00071     BMVContext *c = s->priv_data;
00072     int type;
00073     void *tmp;
00074 
00075     while (c->get_next) {
00076         if (s->pb->eof_reached)
00077             return AVERROR_EOF;
00078         type = avio_r8(s->pb);
00079         if (type == BMV_NOP)
00080             continue;
00081         if (type == BMV_END)
00082             return AVERROR_EOF;
00083         c->size = avio_rl24(s->pb);
00084         if (!c->size)
00085             return AVERROR_INVALIDDATA;
00086         tmp = av_realloc(c->packet, c->size + 1);
00087         if (!tmp)
00088             return AVERROR(ENOMEM);
00089         c->packet = tmp;
00090         c->packet[0] = type;
00091         if (avio_read(s->pb, c->packet + 1, c->size) != c->size)
00092             return AVERROR(EIO);
00093         if (type & BMV_AUDIO) {
00094             int audio_size = c->packet[1] * 65 + 1;
00095             if (audio_size >= c->size) {
00096                 av_log(s, AV_LOG_ERROR, "Reported audio size %d is bigger than packet size (%d)\n",
00097                        audio_size, c->size);
00098                 return AVERROR_INVALIDDATA;
00099             }
00100             if (av_new_packet(pkt, audio_size) < 0)
00101                 return AVERROR(ENOMEM);
00102             memcpy(pkt->data, c->packet + 1, pkt->size);
00103             pkt->stream_index = 1;
00104             pkt->pts          = c->audio_pos;
00105             pkt->duration     = c->packet[1] * 32;
00106             c->audio_pos += pkt->duration;
00107             c->get_next   = 0;
00108             return pkt->size;
00109         } else
00110             break;
00111     }
00112     if (av_new_packet(pkt, c->size + 1) < 0)
00113         return AVERROR(ENOMEM);
00114     pkt->stream_index = 0;
00115     c->get_next = 1;
00116     memcpy(pkt->data, c->packet, pkt->size);
00117     return pkt->size;
00118 }
00119 
00120 static int bmv_read_close(AVFormatContext *s)
00121 {
00122     BMVContext *c = s->priv_data;
00123 
00124     av_freep(&c->packet);
00125 
00126     return 0;
00127 }
00128 
00129 AVInputFormat ff_bmv_demuxer = {
00130     .name           = "bmv",
00131     .long_name      = NULL_IF_CONFIG_SMALL("Discworld II BMV"),
00132     .priv_data_size = sizeof(BMVContext),
00133     .read_header    = bmv_read_header,
00134     .read_packet    = bmv_read_packet,
00135     .read_close     = bmv_read_close,
00136     .extensions     = "bmv"
00137 };
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