static int ac3_eac3_probe(AVProbeData *p, enum AVCodecID expected_codec_id)

{

    int max_frames, first_frames = 0, frames;

    const uint8_t *buf, *buf2, *end;

    enum AVCodecID codec_id = AV_CODEC_ID_AC3;



    max_frames = 0;

    buf = p->buf;

    end = buf + p->buf_size;



    for(; buf < end; buf++) {

        if(buf > p->buf && !(buf[0] == 0x0B && buf[1] == 0x77)

                        && !(buf[0] == 0x77 && buf[1] == 0x0B) )

            continue;

        buf2 = buf;



        for(frames = 0; buf2 < end; frames++) {

            uint8_t buf3[4096];

            uint8_t bitstream_id;

            uint16_t frame_size;

            int i, ret;



            if(!memcmp(buf2, "\x1\x10\0\0\0\0\0\0", 8))

                buf2+=16;

            if (buf[0] == 0x77 && buf[1] == 0x0B) {

                for(i=0; i<8; i+=2) {

                    buf3[i  ] = buf2[i+1];

                    buf3[i+1] = buf2[i  ];

                }

                ret = av_ac3_parse_header(buf3, 8, &bitstream_id,

                                          &frame_size);

            }else

                ret = av_ac3_parse_header(buf2, end - buf2, &bitstream_id,

                                          &frame_size);

            if (ret < 0)

                break;

            if(buf2 + frame_size > end)

                break;

            if (buf[0] == 0x77 && buf[1] == 0x0B) {

                av_assert0(frame_size <= sizeof(buf3));

                for(i = 8; i < frame_size; i += 2) {

                    buf3[i  ] = buf2[i+1];

                    buf3[i+1] = buf2[i  ];

                }

                if (av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf3 + 2, frame_size - 2))

                    break;

            } else {

                if (av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf2 + 2, frame_size - 2))

                    break;

            }

            if (bitstream_id > 10)

                codec_id = AV_CODEC_ID_EAC3;

            buf2 += frame_size;

        }

        max_frames = FFMAX(max_frames, frames);

        if(buf == p->buf)

            first_frames = frames;

    }

    if(codec_id != expected_codec_id) return 0;

    // keep this in sync with mp3 probe, both need to avoid

    // issues with MPEG-files!

    if   (first_frames>=7) return AVPROBE_SCORE_EXTENSION + 1;

    else if(max_frames>200)return AVPROBE_SCORE_EXTENSION;

    else if(max_frames>=4) return AVPROBE_SCORE_EXTENSION/2;

    else if(max_frames>=1) return 1;

    else                   return 0;

}
