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first pass at an experimental 4xm demuxer

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Originally committed as revision 1903 to svn://svn.ffmpeg.org/ffmpeg/trunk
pull/126/head
Mike Melanson 22 years ago
parent 4cfbf61bf1
commit cef4ba9e8a
2 changed files with 282 additions and 1 deletions
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  1. 281
      libavformat/4xm.c
  2. 2
      libavformat/Makefile

281
libavformat/4xm.c
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@ -0,0 +1,281 @@
/*
* 4X Technologies .4xm File Demuxer (no muxer)
* Copyright (c) 2003 The ffmpeg Project
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* @file 4xm.c
* 4X Technologies file demuxer
* by Mike Melanson (melanson@pcisys.net)
* for more information on the .4xm file format, visit:
* http://www.pcisys.net/~melanson/codecs/
*/
#include "avformat.h"
#define LE_16(x) ((((uint8_t*)(x))[1] << 8) | ((uint8_t*)(x))[0])
#define LE_32(x) ((((uint8_t*)(x))[3] << 24) | \
(((uint8_t*)(x))[2] << 16) | \
(((uint8_t*)(x))[1] << 8) | \
((uint8_t*)(x))[0])
#define BE_16(x) ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
#define BE_32(x) ((((uint8_t*)(x))[0] << 24) | \
(((uint8_t*)(x))[1] << 16) | \
(((uint8_t*)(x))[2] << 8) | \
((uint8_t*)(x))[3])
#define FOURCC_TAG( ch0, ch1, ch2, ch3 ) \
( (long)(unsigned char)(ch3) | \
( (long)(unsigned char)(ch2) << 8 ) | \
( (long)(unsigned char)(ch1) << 16 ) | \
( (long)(unsigned char)(ch0) << 24 ) )
#define RIFF_TAG FOURCC_TAG('R', 'I', 'F', 'F')
#define _4XMV_TAG FOURCC_TAG('4', 'X', 'M', 'V')
#define LIST_TAG FOURCC_TAG('L', 'I', 'S', 'T')
#define HEAD_TAG FOURCC_TAG('H', 'E', 'A', 'D')
#define TRK__TAG FOURCC_TAG('T', 'R', 'K', '_')
#define MOVI_TAG FOURCC_TAG('M', 'O', 'V', 'I')
#define VTRK_TAG FOURCC_TAG('V', 'T', 'R', 'K')
#define STRK_TAG FOURCC_TAG('S', 'T', 'R', 'K')
#define name_TAG FOURCC_TAG('n', 'a', 'm', 'e')
#define vtrk_TAG FOURCC_TAG('v', 't', 'r', 'k')
#define strk_TAG FOURCC_TAG('s', 't', 'r', 'k')
#define ifrm_TAG FOURCC_TAG('i', 'f', 'r', 'm')
#define pfrm_TAG FOURCC_TAG('p', 'f', 'r', 'm')
#define cfrm_TAG FOURCC_TAG('c', 'f', 'r', 'm')
#define snd__TAG FOURCC_TAG('s', 'n', 'd', '_')
#define _TAG FOURCC_TAG('', '', '', '')
#define vtrk_SIZE 0x44
#define strk_SIZE 0x28
#define GET_LIST_HEADER() \
fourcc_tag = get_be32(pb); \
size = get_le32(pb); \
if (fourcc_tag != LIST_TAG) \
return AVERROR_INVALIDDATA; \
fourcc_tag = get_be32(pb);
typedef struct AudioTrack {
int sample_rate;
int bits;
int channels;
} AudioTrack;
typedef struct FourxmDemuxContext {
int width;
int height;
int track_count;
AudioTrack *tracks;
int selected_track;
} FourxmDemuxContext;
static int fourxm_probe(AVProbeData *p)
{
if ((BE_32(&p->buf[0]) != RIFF_TAG) ||
(BE_32(&p->buf[8]) != _4XMV_TAG))
return 0;
printf (" detected .4xm file\n");
return AVPROBE_SCORE_MAX;
}
static int fourxm_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
ByteIOContext *pb = &s->pb;
unsigned int fourcc_tag;
unsigned int size;
int header_size;
FourxmDemuxContext *fourxm = (FourxmDemuxContext *)s->priv_data;
unsigned char *header;
int i;
int current_track = -1;
AVStream *st;
fourxm->track_count = 0;
fourxm->tracks = NULL;
fourxm->selected_track = 0;
/* skip the first 3 32-bit numbers */
url_fseek(pb, 12, SEEK_CUR);
/* check for LIST-HEAD */
GET_LIST_HEADER();
header_size = size - 4;
if (fourcc_tag != HEAD_TAG)
return AVERROR_INVALIDDATA;
/* allocate space for the header and load the whole thing */
header = av_malloc(header_size);
if (!header)
return AVERROR_NOMEM;
if (get_buffer(pb, header, header_size) != header_size)
return AVERROR_IO;
/* take the lazy approach and search for any and all vtrk and strk chunks */
for (i = 0; i < header_size - 8; i++) {
fourcc_tag = BE_32(&header[i]);
size = LE_32(&header[i + 4]);
if (fourcc_tag == vtrk_TAG) {
/* check that there is enough data */
if (size != vtrk_SIZE) {
av_free(header);
return AVERROR_INVALIDDATA;
}
fourxm->width = LE_32(&header[i + 36]);
fourxm->height = LE_32(&header[i + 40]);
i += 8 + size;
} else if (fourcc_tag == strk_TAG) {
/* check that there is enough data */
if (size != strk_SIZE) {
av_free(header);
return AVERROR_INVALIDDATA;
}
current_track = LE_32(&header[i + 8]);
if (current_track + 1 > fourxm->track_count) {
fourxm->track_count++;
fourxm->tracks = av_realloc(fourxm->tracks, fourxm->track_count);
if (!fourxm->tracks) {
av_free(header);
return AVERROR_NOMEM;
}
}
fourxm->tracks[current_track].channels = LE_32(&header[i + 36]);
fourxm->tracks[current_track].sample_rate = LE_32(&header[i + 40]);
fourxm->tracks[current_track].bits = LE_32(&header[i + 44]);
i += 8 + size;
}
}
av_free(header);
/* skip over the LIST-MOVI chunk (which is where the stream should be */
GET_LIST_HEADER();
if (fourcc_tag != MOVI_TAG)
return AVERROR_INVALIDDATA;
if (current_track > -1) {
st = av_new_stream(s, 0);
if (!st)
return AVERROR_NOMEM;
st->codec.codec_type = CODEC_TYPE_AUDIO;
st->codec.codec_tag = 1;
st->codec.channels = fourxm->tracks[current_track].channels;
st->codec.sample_rate = fourxm->tracks[current_track].sample_rate;
st->codec.bits_per_sample = fourxm->tracks[current_track].bits;
st->codec.bit_rate = st->codec.channels * st->codec.sample_rate *
st->codec.bits_per_sample;
st->codec.block_align = st->codec.channels * st->codec.bits_per_sample;
if (st->codec.bits_per_sample == 8)
st->codec.codec_id = CODEC_ID_PCM_U8;
else
st->codec.codec_id = CODEC_ID_PCM_S16LE;
}
return 0;
}
static int fourxm_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
FourxmDemuxContext *fourxm = s->priv_data;
ByteIOContext *pb = &s->pb;
unsigned int fourcc_tag;
unsigned int size;
int ret = 0;
int track_number;
int packet_read = 0;
while (!packet_read) {
fourcc_tag = get_be32(pb);
size = get_le32(pb);
if (fourcc_tag == LIST_TAG) {
/* skip the LIST-FRAM tag and get the next fourcc */
get_be32(pb);
fourcc_tag = get_be32(pb);
size = get_le32(pb);
}
if (url_feof(pb))
return -EIO;
switch (fourcc_tag) {
case ifrm_TAG:
case pfrm_TAG:
case cfrm_TAG:
printf (" %cfrm chunk\n", (char)(fourcc_tag >> 24) & 0xFF);
url_fseek(pb, size, SEEK_CUR);
break;
case snd__TAG:
printf (" snd_ chunk, ");
track_number = get_le32(pb);
size = get_le32(pb);
if (track_number == fourxm->selected_track) {
printf ("correct track, dispatching...\n");
if (av_new_packet(pkt, size))
return -EIO;
ret = get_buffer(&s->pb, pkt->data, size);
if (ret < 0)
av_free_packet(pkt);
packet_read = 1;
} else {
printf ("wrong track, skipping...\n");
url_fseek(pb, size, SEEK_CUR);
}
break;
default:
url_fseek(pb, size, SEEK_CUR);
break;
}
}
return ret;
}
static int fourxm_read_close(AVFormatContext *s)
{
FourxmDemuxContext *fourxm = (FourxmDemuxContext *)s->priv_data;
av_free(fourxm->tracks);
return 0;
}
static AVInputFormat fourxm_iformat = {
"4xm",
"4X Technologies format",
sizeof(FourxmDemuxContext),
fourxm_probe,
fourxm_read_header,
fourxm_read_packet,
fourxm_read_close,
};
int fourxm_init(void)
{
av_register_input_format(&fourxm_iformat);
return 0;
}

2
libavformat/Makefile
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@ -14,7 +14,7 @@ PPOBJS=
# mux and demuxes
OBJS+=mpeg.o mpegts.o ffm.o crc.o img.o raw.o rm.o \
avienc.o avidec.o wav.o swf.o au.o gif.o mov.o mpjpeg.o dv.o \
yuv4mpeg.o
yuv4mpeg.o 4xm.o
ifeq ($(CONFIG_RISKY),yes)
OBJS+= asf.o

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