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/*
* Bethsoft VID format Demuxer
* Copyright (c) 2007 Nicholas Tung
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* @brief Bethesda Softworks VID (.vid) file demuxer
* @author Nicholas Tung [ntung (at. ntung com] (2007-03)
* @sa http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
* @sa http://www.svatopluk.com/andux/docs/dfvid.html
*/
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "libavcodec/bethsoftvideo.h"
typedef struct BVID_DemuxContext
{
int nframes;
/** delay value between frames, added to individual frame delay.
* custom units, which will be added to other custom units (~=16ms according
* to free, unofficial documentation) */
int bethsoft_global_delay;
/** video presentation time stamp.
* delay = 16 milliseconds * (global_delay + per_frame_delay) */
int video_pts;
int is_finished;
} BVID_DemuxContext;
static int vid_probe(AVProbeData *p)
{
// little endian VID tag, file starts with "VID\0"
if (AV_RL32(p->buf) != MKTAG('V', 'I', 'D', 0))
return 0;
return AVPROBE_SCORE_MAX;
}
static int vid_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
BVID_DemuxContext *vid = s->priv_data;
AVIOContext *pb = s->pb;
AVStream *stream;
/* load main header. Contents:
* bytes: 'V' 'I' 'D'
* int16s: always_512, nframes, width, height, delay, always_14
*/
avio_skip(pb, 5);
vid->nframes = avio_rl16(pb);
stream = av_new_stream(s, 0);
if (!stream)
return AVERROR(ENOMEM);
av_set_pts_info(stream, 32, 1, 60); // 16 ms increments, i.e. 60 fps
stream->codec->codec_type = AVMEDIA_TYPE_VIDEO;
stream->codec->codec_id = CODEC_ID_BETHSOFTVID;
stream->codec->width = avio_rl16(pb);
stream->codec->height = avio_rl16(pb);
stream->codec->pix_fmt = PIX_FMT_PAL8;
vid->bethsoft_global_delay = avio_rl16(pb);
avio_rl16(pb);
// done with video codec, set up audio codec
stream = av_new_stream(s, 0);
if (!stream)
return AVERROR(ENOMEM);
stream->codec->codec_type = AVMEDIA_TYPE_AUDIO;
stream->codec->codec_id = CODEC_ID_PCM_U8;
stream->codec->channels = 1;
stream->codec->sample_rate = 11025;
stream->codec->bits_per_coded_sample = 8;
stream->codec->bit_rate = stream->codec->channels * stream->codec->sample_rate * stream->codec->bits_per_coded_sample;
return 0;
}
#define BUFFER_PADDING_SIZE 1000
static int read_frame(BVID_DemuxContext *vid, AVIOContext *pb, AVPacket *pkt,
uint8_t block_type, AVFormatContext *s, int npixels)
{
uint8_t * vidbuf_start = NULL;
int vidbuf_nbytes = 0;
int code;
int bytes_copied = 0;
int position;
unsigned int vidbuf_capacity;
vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
if(!vidbuf_start)
return AVERROR(ENOMEM);
// save the file position for the packet, include block type
position = avio_tell(pb) - 1;
vidbuf_start[vidbuf_nbytes++] = block_type;
// get the video delay (next int16), and set the presentation time
vid->video_pts += vid->bethsoft_global_delay + avio_rl16(pb);
// set the y offset if it exists (decoder header data should be in data section)
if(block_type == VIDEO_YOFF_P_FRAME){
if(avio_read(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2)
goto fail;
vidbuf_nbytes += 2;
}
do{
vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE);
if(!vidbuf_start)
return AVERROR(ENOMEM);
code = avio_r8(pb);
vidbuf_start[vidbuf_nbytes++] = code;
if(code >= 0x80){ // rle sequence
if(block_type == VIDEO_I_FRAME)
vidbuf_start[vidbuf_nbytes++] = avio_r8(pb);
} else if(code){ // plain sequence
if(avio_read(pb, &vidbuf_start[vidbuf_nbytes], code) != code)
goto fail;
vidbuf_nbytes += code;
}
bytes_copied += code & 0x7F;
if(bytes_copied == npixels){ // sometimes no stop character is given, need to keep track of bytes copied
// may contain a 0 byte even if read all pixels
if(avio_r8(pb))
avio_seek(pb, -1, SEEK_CUR);
break;
}
if(bytes_copied > npixels)
goto fail;
} while(code);
// copy data into packet
if(av_new_packet(pkt, vidbuf_nbytes) < 0)
goto fail;
memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);
av_free(vidbuf_start);
pkt->pos = position;
pkt->stream_index = 0; // use the video decoder, which was initialized as the first stream
pkt->pts = vid->video_pts;
vid->nframes--; // used to check if all the frames were read
return vidbuf_nbytes;
fail:
av_free(vidbuf_start);
return -1;
}
static int vid_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
BVID_DemuxContext *vid = s->priv_data;
AVIOContext *pb = s->pb;
unsigned char block_type;
int audio_length;
int ret_value;
if(vid->is_finished || pb->eof_reached)
return AVERROR(EIO);
block_type = avio_r8(pb);
switch(block_type){
case PALETTE_BLOCK:
avio_seek(pb, -1, SEEK_CUR); // include block type
ret_value = av_get_packet(pb, pkt, 3 * 256 + 1);
if(ret_value != 3 * 256 + 1){
av_free_packet(pkt);
return AVERROR(EIO);
}
pkt->stream_index = 0;
return ret_value;
case FIRST_AUDIO_BLOCK:
avio_rl16(pb);
// soundblaster DAC used for sample rate, as on specification page (link above)
s->streams[1]->codec->sample_rate = 1000000 / (256 - avio_r8(pb));
s->streams[1]->codec->bit_rate = s->streams[1]->codec->channels * s->streams[1]->codec->sample_rate * s->streams[1]->codec->bits_per_coded_sample;
case AUDIO_BLOCK:
audio_length = avio_rl16(pb);
ret_value = av_get_packet(pb, pkt, audio_length);
pkt->stream_index = 1;
return ret_value != audio_length ? AVERROR(EIO) : ret_value;
case VIDEO_P_FRAME:
case VIDEO_YOFF_P_FRAME:
case VIDEO_I_FRAME:
return read_frame(vid, pb, pkt, block_type, s,
s->streams[0]->codec->width * s->streams[0]->codec->height);
case EOF_BLOCK:
if(vid->nframes != 0)
av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");
vid->is_finished = 1;
return AVERROR(EIO);
default:
av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",
block_type, block_type, block_type); return -1;
}
return 0;
}
AVInputFormat ff_bethsoftvid_demuxer = {
"bethsoftvid",
NULL_IF_CONFIG_SMALL("Bethesda Softworks VID format"),
sizeof(BVID_DemuxContext),
vid_probe,
vid_read_header,
vid_read_packet,
};
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