if ((opcode_version > 0) || (opcode_size > 6)) {                debug_ipmovie("bad create_timer opcode\n");                chunk_type = CHUNK_BAD;                break;            }            if (get_buffer(pb, scratch, opcode_size) !=                opcode_size) {                chunk_type = CHUNK_BAD;                break;            }            s->fps = 1000000.0 / (LE_32(&scratch[0]) * LE_16(&scratch[4]));            s->frame_pts_inc = 90000 / s->fps;            debug_ipmovie("  %.2f frames/second (timer div = %d, subdiv = %d)\n",                s->fps, LE_32(&scratch[0]), LE_16(&scratch[4]));            break;        case OPCODE_INIT_AUDIO_BUFFERS:            debug_ipmovie("initialize audio buffers\n");            if ((opcode_version > 1) || (opcode_size > 10)) {                debug_ipmovie("bad init_audio_buffers opcode\n");                chunk_type = CHUNK_BAD;                break;            }            if (get_buffer(pb, scratch, opcode_size) !=                opcode_size) {                chunk_type = CHUNK_BAD;                break;            }            s->audio_sample_rate = LE_16(&scratch[4]);            audio_flags = LE_16(&scratch[2]);            /* bit 0 of the flags: 0 = mono, 1 = stereo */            s->audio_channels = (audio_flags & 1) + 1;            /* bit 1 of the flags: 0 = 8 bit, 1 = 16 bit */            s->audio_bits = (((audio_flags >> 1) & 1) + 1) * 8;            /* bit 2 indicates compressed audio in version 1 opcode */            if ((opcode_version == 1) && (audio_flags & 0x4))                s->audio_type = CODEC_ID_INTERPLAY_DPCM;            else if (s->audio_bits == 16)                s->audio_type = CODEC_ID_PCM_S16LE;            else                s->audio_type = CODEC_ID_PCM_U8;            debug_ipmovie("audio: %d bits, %d Hz, %s, %s format\n",                s->audio_bits,                s->audio_sample_rate,                (s->audio_channels == 2) ? "stereo" : "mono",                (s->audio_type == CODEC_ID_INTERPLAY_DPCM) ?                 "Interplay audio" : "PCM");            break;        case OPCODE_START_STOP_AUDIO:            debug_ipmovie("start/stop audio\n");            url_fseek(pb, opcode_size, SEEK_CUR);            break;        case OPCODE_INIT_VIDEO_BUFFERS:            debug_ipmovie("initialize video buffers\n");            if ((opcode_version > 2) || (opcode_size > 8)) {                debug_ipmovie("bad init_video_buffers opcode\n");                chunk_type = CHUNK_BAD;                break;            }            if (get_buffer(pb, scratch, opcode_size) !=                opcode_size) {                chunk_type = CHUNK_BAD;                break;            }            s->video_width = LE_16(&scratch[0]) * 8;            s->video_height = LE_16(&scratch[2]) * 8;            debug_ipmovie("video resolution: %d x %d\n",                s->video_width, s->video_height);            break;        case OPCODE_UNKNOWN_06:        case OPCODE_UNKNOWN_0E:        case OPCODE_UNKNOWN_10:        case OPCODE_UNKNOWN_12:        case OPCODE_UNKNOWN_13:        case OPCODE_UNKNOWN_14:        case OPCODE_UNKNOWN_15:            debug_ipmovie("unknown (but documented) opcode %02X\n", opcode_type);            url_fseek(pb, opcode_size, SEEK_CUR);            break;        case OPCODE_SEND_BUFFER:            debug_ipmovie("send buffer\n");            url_fseek(pb, opcode_size, SEEK_CUR);            break;        case OPCODE_AUDIO_FRAME:            debug_ipmovie("audio frame\n");            /* log position and move on for now */            s->audio_chunk_offset = url_ftell(pb);            s->audio_chunk_size = opcode_size;            url_fseek(pb, opcode_size, SEEK_CUR);            break;        case OPCODE_SILENCE_FRAME:            debug_ipmovie("silence frame\n");            url_fseek(pb, opcode_size, SEEK_CUR);            break;        case OPCODE_INIT_VIDEO_MODE:            debug_ipmovie("initialize video mode\n");            url_fseek(pb, opcode_size, SEEK_CUR);            break;        case OPCODE_CREATE_GRADIENT:            debug_ipmovie("create gradient\n");            url_fseek(pb, opcode_size, SEEK_CUR);            break;        case OPCODE_SET_PALETTE:            debug_ipmovie("set palette\n");            /* check for the logical maximum palette size             * (3 * 256 + 4 bytes) */            if (opcode_size > 0x304) {                debug_ipmovie("demux_ipmovie: set_palette opcode too large\n");                chunk_type = CHUNK_BAD;                break;            }            if (get_buffer(pb, scratch, opcode_size) != opcode_size) {                chunk_type = CHUNK_BAD;                break;            }            /* load the palette into internal data structure */            first_color = LE_16(&scratch[0]);            last_color = first_color + LE_16(&scratch[2]) - 1;            /* sanity check (since they are 16 bit values) */            if ((first_color > 0xFF) || (last_color > 0xFF)) {                debug_ipmovie("demux_ipmovie: set_palette indices out of range (%d -> %d)\n",                    first_color, last_color);                chunk_type = CHUNK_BAD;                break;            }            j = 4;  /* offset of first palette data */            for (i = first_color; i <= last_color; i++) {                /* the palette is stored as a 6-bit VGA palette, thus each                 * component is shifted up to a 8-bit range */                r = scratch[j++] * 4;                g = scratch[j++] * 4;                b = scratch[j++] * 4;                s->palette_control.palette[i] = (r << 16) | (g << 8) | (b);            }            /* indicate a palette change */            s->palette_control.palette_changed = 1;            break;        case OPCODE_SET_PALETTE_COMPRESSED:            debug_ipmovie("set palette compressed\n");            url_fseek(pb, opcode_size, SEEK_CUR);            break;        case OPCODE_SET_DECODING_MAP:            debug_ipmovie("set decoding map\n");            /* log position and move on for now */            s->decode_map_chunk_offset = url_ftell(pb);            s->decode_map_chunk_size = opcode_size;            url_fseek(pb, opcode_size, SEEK_CUR);            break;        case OPCODE_VIDEO_DATA:            debug_ipmovie("set video data\n");            /* log position and move on for now */            s->video_chunk_offset = url_ftell(pb);            s->video_chunk_size = opcode_size;            url_fseek(pb, opcode_size, SEEK_CUR);            break;        default:            debug_ipmovie("*** unknown opcode type\n");            chunk_type = CHUNK_BAD;            break;        }    }    /* make a note of where the stream is sitting */    s->next_chunk_offset = url_ftell(pb);    /* dispatch the first of any pending packets */    if ((chunk_type == CHUNK_VIDEO) || (chunk_type == CHUNK_AUDIO_ONLY))        chunk_type = load_ipmovie_packet(s, pb, pkt);    return chunk_type;}static int ipmovie_probe(AVProbeData *p){    if (p->buf_size < IPMOVIE_SIGNATURE_SIZE)        return 0;    if (strncmp(p->buf, IPMOVIE_SIGNATURE, IPMOVIE_SIGNATURE_SIZE) != 0)        return 0;    return AVPROBE_SCORE_MAX;}static int ipmovie_read_header(AVFormatContext *s,                               AVFormatParameters *ap){    IPMVEContext *ipmovie = (IPMVEContext *)s->priv_data;    ByteIOContext *pb = &s->pb;    AVPacket pkt;    AVStream *st;    unsigned char chunk_preamble[CHUNK_PREAMBLE_SIZE];    int chunk_type;    /* initialize private context members */    ipmovie->video_pts = ipmovie->audio_frame_count = 0;    ipmovie->audio_chunk_offset = ipmovie->video_chunk_offset =    ipmovie->decode_map_chunk_offset = 0;    /* on the first read, this will position the stream at the first chunk */    ipmovie->next_chunk_offset = IPMOVIE_SIGNATURE_SIZE + 6;    /* process the first chunk which should be CHUNK_INIT_VIDEO */    if (process_ipmovie_chunk(ipmovie, pb, &pkt) != CHUNK_INIT_VIDEO)        return AVERROR_INVALIDDATA;    /* peek ahead to the next chunk-- if it is an init audio chunk, process     * it; if it is the first video chunk, this is a silent file */    if (get_buffer(pb, chunk_preamble, CHUNK_PREAMBLE_SIZE) !=        CHUNK_PREAMBLE_SIZE)        return -EIO;    chunk_type = LE_16(&chunk_preamble[2]);    url_fseek(pb, -CHUNK_PREAMBLE_SIZE, SEEK_CUR);    if (chunk_type == CHUNK_VIDEO)        ipmovie->audio_type = 0;  /* no audio */    else if (process_ipmovie_chunk(ipmovie, pb, &pkt) != CHUNK_INIT_AUDIO)        return AVERROR_INVALIDDATA;    /* set the pts reference (1 pts = 1/90000) */    s->pts_num = 1;    s->pts_den = 90000;    /* initialize the stream decoders */    st = av_new_stream(s, 0);    if (!st)        return AVERROR_NOMEM;    ipmovie->video_stream_index = st->index;    st->codec.codec_type = CODEC_TYPE_VIDEO;    st->codec.codec_id = CODEC_ID_INTERPLAY_VIDEO;    st->codec.codec_tag = 0;  /* no fourcc */    st->codec.width = ipmovie->video_width;    st->codec.height = ipmovie->video_height;    /* palette considerations */    st->codec.palctrl = &ipmovie->palette_control;    if (ipmovie->audio_type) {        st = av_new_stream(s, 0);        if (!st)            return AVERROR_NOMEM;        ipmovie->audio_stream_index = st->index;        st->codec.codec_type = CODEC_TYPE_AUDIO;        st->codec.codec_id = ipmovie->audio_type;        st->codec.codec_tag = 0;  /* no tag */        st->codec.channels = ipmovie->audio_channels;        st->codec.sample_rate = ipmovie->audio_sample_rate;        st->codec.bits_per_sample = ipmovie->audio_bits;        st->codec.bit_rate = st->codec.channels * st->codec.sample_rate *            st->codec.bits_per_sample;        if (st->codec.codec_id == CODEC_ID_INTERPLAY_DPCM)            st->codec.bit_rate /= 2;        st->codec.block_align = st->codec.channels * st->codec.bits_per_sample;    }    return 0;}static int ipmovie_read_packet(AVFormatContext *s,                               AVPacket *pkt){    IPMVEContext *ipmovie = (IPMVEContext *)s->priv_data;    ByteIOContext *pb = &s->pb;    int ret;    ret = process_ipmovie_chunk(ipmovie, pb, pkt);    if (ret == CHUNK_BAD)        ret = AVERROR_INVALIDDATA;    else if (ret == CHUNK_EOF)        ret = -EIO;    else if (ret == CHUNK_NOMEM)        ret = AVERROR_NOMEM;    else        ret = 0;    return ret;}static int ipmovie_read_close(AVFormatContext *s){//    IPMVEContext *ipmovie = (IPMVEContext *)s->priv_data;    return 0;}static AVInputFormat ipmovie_iformat = {    "ipmovie",    "Interplay MVE format",    sizeof(IPMVEContext),    ipmovie_probe,    ipmovie_read_header,    ipmovie_read_packet,    ipmovie_read_close,};int ipmovie_init(void){    av_register_input_format(&ipmovie_iformat);    return 0;}