apc.c File Reference

#include <string.h>
#include "avformat.h"

Go to the source code of this file.

Defines
#define	MAX_READ_SIZE   4096
Functions
static int	apc_probe (AVProbeData *p)
static int	apc_read_header (AVFormatContext *s, AVFormatParameters *ap)
static int	apc_read_packet (AVFormatContext *s, AVPacket *pkt)
Variables
AVInputFormat	apc_demuxer

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Define Documentation

#define MAX_READ_SIZE   4096

Definition at line 73 of file apc.c.

Referenced by apc_read_packet().

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Function Documentation

static int apc_probe

(

AVProbeData *

p

)

[static]

Definition at line 25 of file apc.c.

References AVPROBE_SCORE_MAX, and AVProbeData::buf.

{
    if (!strncmp(p->buf, "CRYO_APC", 8))
        return AVPROBE_SCORE_MAX;

    return 0;
}

static int apc_read_header	(	AVFormatContext *	s,
		AVFormatParameters *	ap
	)			[static]

Definition at line 33 of file apc.c.

References av_malloc(), av_new_stream(), AVERROR, AVCodecContext::bit_rate, AVCodecContext::bits_per_sample, AVCodecContext::block_align, AVCodecContext::channels, AVStream::codec, AVCodecContext::codec_id, CODEC_ID_ADPCM_IMA_WS, AVCodecContext::codec_type, CODEC_TYPE_AUDIO, AVCodecContext::extradata, AVCodecContext::extradata_size, FF_INPUT_BUFFER_PADDING_SIZE, get_buffer(), get_le32(), AVFormatContext::pb, and AVCodecContext::sample_rate.

{
    ByteIOContext *pb = s->pb;
    AVStream *st;

    get_le32(pb); /* CRYO */
    get_le32(pb); /* _APC */
    get_le32(pb); /* 1.20 */

    st = av_new_stream(s, 0);
    if (!st)
        return AVERROR(ENOMEM);

    st->codec->codec_type = CODEC_TYPE_AUDIO;
    st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS;

    get_le32(pb); /* number of samples */
    st->codec->sample_rate = get_le32(pb);

    st->codec->extradata_size = 2 * 4;
    st->codec->extradata = av_malloc(st->codec->extradata_size +
                                     FF_INPUT_BUFFER_PADDING_SIZE);
    if (!st->codec->extradata)
        return AVERROR(ENOMEM);

    /* initial predictor values for adpcm decoder */
    get_buffer(pb, st->codec->extradata, 2 * 4);

    st->codec->channels = 1;
    if (get_le32(pb))
        st->codec->channels = 2;

    st->codec->bits_per_sample = 4;
    st->codec->bit_rate = st->codec->bits_per_sample * st->codec->channels
                          * st->codec->sample_rate;
    st->codec->block_align = 1;

    return 0;
}

static int apc_read_packet	(	AVFormatContext *	s,
		AVPacket *	pkt
	)			[static]

Definition at line 75 of file apc.c.

References av_get_packet(), AVERROR, MAX_READ_SIZE, AVFormatContext::pb, and AVPacket::stream_index.

{
    if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0)
        return AVERROR(EIO);
    pkt->stream_index = 0;
    return 0;
}

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Variable Documentation

AVInputFormat apc_demuxer

Initial value:

 {
    "apc",
    NULL_IF_CONFIG_SMALL("CRYO APC format"),
    0,
    apc_probe,
    apc_read_header,
    apc_read_packet,
}

Definition at line 83 of file apc.c.

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