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ffmpeg/libavformat/4xm.c

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/*
* 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 RIFF_TAG MKTAG('R', 'I', 'F', 'F')
#define _4XMV_TAG MKTAG('4', 'X', 'M', 'V')
#define LIST_TAG MKTAG('L', 'I', 'S', 'T')
#define HEAD_TAG MKTAG('H', 'E', 'A', 'D')
#define TRK__TAG MKTAG('T', 'R', 'K', '_')
#define MOVI_TAG MKTAG('M', 'O', 'V', 'I')
#define VTRK_TAG MKTAG('V', 'T', 'R', 'K')
#define STRK_TAG MKTAG('S', 'T', 'R', 'K')
#define std__TAG MKTAG('s', 't', 'd', '_')
#define name_TAG MKTAG('n', 'a', 'm', 'e')
#define vtrk_TAG MKTAG('v', 't', 'r', 'k')
#define strk_TAG MKTAG('s', 't', 'r', 'k')
#define ifrm_TAG MKTAG('i', 'f', 'r', 'm')
#define pfrm_TAG MKTAG('p', 'f', 'r', 'm')
#define cfrm_TAG MKTAG('c', 'f', 'r', 'm')
#define snd__TAG MKTAG('s', 'n', 'd', '_')
#define vtrk_SIZE 0x44
#define strk_SIZE 0x28
#define GET_LIST_HEADER() \
fourcc_tag = get_le32(pb); \
size = get_le32(pb); \
if (fourcc_tag != LIST_TAG) \
return AVERROR_INVALIDDATA; \
fourcc_tag = get_le32(pb);
typedef struct AudioTrack {
int sample_rate;
int bits;
int channels;
int stream_index;
int adpcm;
} AudioTrack;
typedef struct FourxmDemuxContext {
int width;
int height;
int video_stream_index;
int track_count;
AudioTrack *tracks;
int selected_track;
int64_t audio_pts;
int64_t video_pts;
int video_pts_inc;
float fps;
} FourxmDemuxContext;
static float get_le_float(unsigned char *buffer)
{
float f;
unsigned char *float_buffer = (unsigned char *)&f;
#ifdef WORDS_BIGENDIAN
float_buffer[0] = buffer[3];
float_buffer[1] = buffer[2];
float_buffer[2] = buffer[1];
float_buffer[3] = buffer[0];
#else
float_buffer[0] = buffer[0];
float_buffer[1] = buffer[1];
float_buffer[2] = buffer[2];
float_buffer[3] = buffer[3];
#endif
return f;
}
static int fourxm_probe(AVProbeData *p)
{
if (p->buf_size < 12)
return 0;
if ((LE_32(&p->buf[0]) != RIFF_TAG) ||
(LE_32(&p->buf[8]) != _4XMV_TAG))
return 0;
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;
fourxm->fps = 1.0;
/* 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 = LE_32(&header[i]);
size = LE_32(&header[i + 4]);
if (fourcc_tag == std__TAG) {
fourxm->fps = get_le_float(&header[i + 12]);
fourxm->video_pts_inc = (int)(90000.0 / fourxm->fps);
} else 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;
/* allocate a new AVStream */
st = av_new_stream(s, 0);
if (!st)
return AVERROR_NOMEM;
av_set_pts_info(st, 33, 1, 90000);
fourxm->video_stream_index = st->index;
st->codec.frame_rate = fourxm->fps;
st->codec.frame_rate_base = 1.0;
st->codec.codec_type = CODEC_TYPE_VIDEO;
st->codec.codec_id = CODEC_ID_4XM;
st->codec.codec_tag = 0; /* no fourcc */
st->codec.width = fourxm->width;
st->codec.height = fourxm->height;
} 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 = current_track + 1;
fourxm->tracks = av_realloc(fourxm->tracks,
fourxm->track_count * sizeof(AudioTrack));
if (!fourxm->tracks) {
av_free(header);
return AVERROR_NOMEM;
}
}
fourxm->tracks[current_track].adpcm = LE_32(&header[i + 12]);
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;
/* allocate a new AVStream */
st = av_new_stream(s, current_track);
if (!st)
return AVERROR_NOMEM;
/* set the pts reference (1 pts = 1/90000) */
av_set_pts_info(st, 33, 1, 90000);
fourxm->tracks[current_track].stream_index = st->index;
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 (fourxm->tracks[current_track].adpcm)
st->codec.codec_id = CODEC_ID_ADPCM_4XM;
else if (st->codec.bits_per_sample == 8)
st->codec.codec_id = CODEC_ID_PCM_U8;
else
st->codec.codec_id = CODEC_ID_PCM_S16LE;
}
}
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;
/* initialize context members */
fourxm->video_pts = -fourxm->video_pts_inc; /* first frame will push to 0 */
fourxm->audio_pts = 0;
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, out_size;
int ret = 0;
int track_number;
int packet_read = 0;
unsigned char header[8];
int64_t pts_inc;
int audio_frame_count;
while (!packet_read) {
if ((ret = get_buffer(&s->pb, header, 8)) < 0)
return ret;
fourcc_tag = LE_32(&header[0]);
size = LE_32(&header[4]);
if (url_feof(pb))
return AVERROR_IO;
switch (fourcc_tag) {
case LIST_TAG:
/* this is a good time to bump the video pts */
fourxm->video_pts += fourxm->video_pts_inc;
/* skip the LIST-* tag and move on to the next fourcc */
get_le32(pb);
break;
case ifrm_TAG:
case pfrm_TAG:
case cfrm_TAG:{
/* allocate 8 more bytes than 'size' to account for fourcc
* and size */
if (av_new_packet(pkt, size + 8))
return AVERROR_IO;
pkt->stream_index = fourxm->video_stream_index;
pkt->pts = fourxm->video_pts;
memcpy(pkt->data, header, 8);
ret = get_buffer(&s->pb, &pkt->data[8], size);
if (ret < 0)
av_free_packet(pkt);
else
packet_read = 1;
break;
}
case snd__TAG:
track_number = get_le32(pb);
out_size= get_le32(pb);
size-=8;
if (track_number == fourxm->selected_track) {
if (av_new_packet(pkt, size))
return AVERROR_IO;
pkt->stream_index =
fourxm->tracks[fourxm->selected_track].stream_index;
pkt->pts = fourxm->audio_pts;
ret = get_buffer(&s->pb, pkt->data, size);
if (ret < 0)
av_free_packet(pkt);
else
packet_read = 1;
/* pts accounting */
audio_frame_count = size;
if (fourxm->tracks[fourxm->selected_track].adpcm)
audio_frame_count -=
2 * (fourxm->tracks[fourxm->selected_track].channels);
audio_frame_count /=
fourxm->tracks[fourxm->selected_track].channels;
if (fourxm->tracks[fourxm->selected_track].adpcm)
audio_frame_count *= 2;
else
audio_frame_count /=
(fourxm->tracks[fourxm->selected_track].bits / 8);
pts_inc = audio_frame_count;
pts_inc *= 90000;
pts_inc /= fourxm->tracks[fourxm->selected_track].sample_rate;
fourxm->audio_pts += pts_inc;
} else {
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;
}
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