static int ea_read_header(AVFormatContext *s)

{

    EaDemuxContext *ea = s->priv_data;

    AVStream *st;



    if (process_ea_header(s)<=0)

        return AVERROR(EIO);



    if (init_video_stream(s, &ea->video) || init_video_stream(s, &ea->alpha))

        return AVERROR(ENOMEM);



    if (ea->audio_codec) {

        if (ea->num_channels <= 0 || ea->num_channels > 2) {

            av_log(s, AV_LOG_WARNING,

                   "Unsupported number of channels: %d\n", ea->num_channels);

            ea->audio_codec = 0;

            return 1;

        }

        if (ea->sample_rate <= 0) {

            av_log(s, AV_LOG_ERROR,

                   "Unsupported sample rate: %d\n", ea->sample_rate);

            ea->audio_codec = 0;

            return 1;

        }

        if (ea->bytes <= 0) {

            av_log(s, AV_LOG_ERROR,

                   "Invalid number of bytes per sample: %d\n", ea->bytes);

            ea->audio_codec = AV_CODEC_ID_NONE;

            return 1;

        }



        /* initialize the audio decoder stream */

        st = avformat_new_stream(s, NULL);

        if (!st)

            return AVERROR(ENOMEM);

        avpriv_set_pts_info(st, 33, 1, ea->sample_rate);

        st->codecpar->codec_type            = AVMEDIA_TYPE_AUDIO;

        st->codecpar->codec_id              = ea->audio_codec;

        st->codecpar->codec_tag             = 0;   /* no tag */

        st->codecpar->channels              = ea->num_channels;

        st->codecpar->sample_rate           = ea->sample_rate;

        st->codecpar->bits_per_coded_sample = ea->bytes * 8;

        st->codecpar->bit_rate              = (int64_t)st->codecpar->channels *

                                              st->codecpar->sample_rate *

                                              st->codecpar->bits_per_coded_sample / 4;

        st->codecpar->block_align           = st->codecpar->channels *

                                              st->codecpar->bits_per_coded_sample;

        ea->audio_stream_index           = st->index;

        st->start_time                   = 0;

    }



    return 1;

}
