/*

 * Interplay MVE File Demuxer

 * Copyright (c) 2003 The FFmpeg project

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg 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 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg 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 FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file

 * Interplay MVE file demuxer

 * by Mike Melanson (melanson@pcisys.net)

 * For more information regarding the Interplay MVE file format, visit:

 *   http://www.pcisys.net/~melanson/codecs/

 * The aforementioned site also contains a command line utility for parsing

 * IP MVE files so that you can get a good idea of the typical structure of

 * such files. This demuxer is not the best example to use if you are trying

 * to write your own as it uses a rather roundabout approach for splitting

 * up and sending out the chunks.

 */

#include "libavutil/channel_layout.h"

#include "libavutil/intreadwrite.h"

#include "avformat.h"

#include "avio_internal.h"

#include "demux.h"

#include "internal.h"

#define CHUNK_PREAMBLE_SIZE 4

#define OPCODE_PREAMBLE_SIZE 4

#define CHUNK_INIT_AUDIO   0x0000

#define CHUNK_AUDIO_ONLY   0x0001

#define CHUNK_INIT_VIDEO   0x0002

#define CHUNK_VIDEO        0x0003

#define CHUNK_SHUTDOWN     0x0004

#define CHUNK_END          0x0005

/* these last types are used internally */

#define CHUNK_HAVE_PACKET  0xFFFB

#define CHUNK_DONE         0xFFFC

#define CHUNK_NOMEM        0xFFFD

#define CHUNK_EOF          0xFFFE

#define CHUNK_BAD          0xFFFF

#define OPCODE_END_OF_STREAM           0x00

#define OPCODE_END_OF_CHUNK            0x01

#define OPCODE_CREATE_TIMER            0x02

#define OPCODE_INIT_AUDIO_BUFFERS      0x03

#define OPCODE_START_STOP_AUDIO        0x04

#define OPCODE_INIT_VIDEO_BUFFERS      0x05

#define OPCODE_VIDEO_DATA_06           0x06

#define OPCODE_SEND_BUFFER             0x07

#define OPCODE_AUDIO_FRAME             0x08

#define OPCODE_SILENCE_FRAME           0x09

#define OPCODE_INIT_VIDEO_MODE         0x0A

#define OPCODE_CREATE_GRADIENT         0x0B

#define OPCODE_SET_PALETTE             0x0C

#define OPCODE_SET_PALETTE_COMPRESSED  0x0D

#define OPCODE_SET_SKIP_MAP            0x0E

#define OPCODE_SET_DECODING_MAP        0x0F

#define OPCODE_VIDEO_DATA_10           0x10

#define OPCODE_VIDEO_DATA_11           0x11

#define OPCODE_UNKNOWN_12              0x12

#define OPCODE_UNKNOWN_13              0x13

#define OPCODE_UNKNOWN_14              0x14

#define OPCODE_UNKNOWN_15              0x15

#define PALETTE_COUNT 256

typedef struct IPMVEContext {

    AVFormatContext *avf;

    unsigned char *buf;

    int buf_size;

    uint64_t frame_pts_inc;

    unsigned int video_bpp;

    unsigned int video_width;

    unsigned int video_height;

    int64_t video_pts;

    uint32_t     palette[256];

    int          has_palette;

    int          changed;

    uint8_t      send_buffer;

    uint8_t      frame_format;

    unsigned int audio_bits;

    unsigned int audio_channels;

    unsigned int audio_sample_rate;

    enum AVCodecID audio_type;

    unsigned int audio_frame_count;

    int video_stream_index;

    int audio_stream_index;

    int64_t audio_chunk_offset;

    int audio_chunk_size;

    int64_t video_chunk_offset;

    int video_chunk_size;

    int64_t skip_map_chunk_offset;

    int skip_map_chunk_size;

    int64_t decode_map_chunk_offset;

    int decode_map_chunk_size;

    int64_t next_chunk_offset;

} IPMVEContext;

static int load_ipmovie_packet(IPMVEContext *s, AVIOContext *pb,

    AVPacket *pkt) {

    int chunk_type;

    if (s->audio_chunk_offset && s->audio_channels && s->audio_bits) {

        if (s->audio_type == AV_CODEC_ID_NONE) {

            av_log(s->avf, AV_LOG_ERROR, "Can not read audio packet before"

                   "audio codec is known\n");

                return CHUNK_BAD;

        }

        /* adjust for PCM audio by skipping chunk header */

        if (s->audio_type != AV_CODEC_ID_INTERPLAY_DPCM) {

            s->audio_chunk_offset += 6;

            s->audio_chunk_size -= 6;

        }

        avio_seek(pb, s->audio_chunk_offset, SEEK_SET);

        s->audio_chunk_offset = 0;

        if (s->audio_chunk_size != av_get_packet(pb, pkt, s->audio_chunk_size))

            return CHUNK_EOF;

        pkt->stream_index = s->audio_stream_index;

        pkt->pts = s->audio_frame_count;

        /* audio frame maintenance */

        if (s->audio_type != AV_CODEC_ID_INTERPLAY_DPCM)

            s->audio_frame_count +=

            (s->audio_chunk_size / s->audio_channels / (s->audio_bits / 8));

        else

            s->audio_frame_count +=

                (s->audio_chunk_size - 6 - s->audio_channels) / s->audio_channels;

        av_log(s->avf, AV_LOG_TRACE, "sending audio frame with pts %"PRId64" (%d audio frames)\n",

                pkt->pts, s->audio_frame_count);

        chunk_type = CHUNK_HAVE_PACKET;

    } else if (s->frame_format) {

        /* send the frame format, decode map, the video data, skip map, and the send_buffer flag together */

        if (av_new_packet(pkt, 8 + s->decode_map_chunk_size + s->video_chunk_size + s->skip_map_chunk_size))

            return CHUNK_NOMEM;

        if (s->has_palette) {

            uint8_t *pal;

            pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,

                                          AVPALETTE_SIZE);

            if (pal) {

                memcpy(pal, s->palette, AVPALETTE_SIZE);

                s->has_palette = 0;

            }

        }

        if (s->changed) {

            ff_add_param_change(pkt, 0, 0, 0, s->video_width, s->video_height);

            s->changed = 0;

        }

        AV_WL8(pkt->data, s->frame_format);

        AV_WL8(pkt->data + 1, s->send_buffer);

        AV_WL16(pkt->data + 2, s->video_chunk_size);

        AV_WL16(pkt->data + 4, s->decode_map_chunk_size);

        AV_WL16(pkt->data + 6, s->skip_map_chunk_size);

        s->frame_format = 0;

        s->send_buffer = 0;

        pkt->pos = s->video_chunk_offset;

        avio_seek(pb, s->video_chunk_offset, SEEK_SET);

        s->video_chunk_offset = 0;

        if (avio_read(pb, pkt->data + 8, s->video_chunk_size) !=

            s->video_chunk_size) {

            return CHUNK_EOF;

        }

        if (s->decode_map_chunk_size) {

            pkt->pos = s->decode_map_chunk_offset;

            avio_seek(pb, s->decode_map_chunk_offset, SEEK_SET);

            s->decode_map_chunk_offset = 0;

            if (avio_read(pb, pkt->data + 8 + s->video_chunk_size,

                s->decode_map_chunk_size) != s->decode_map_chunk_size) {

                return CHUNK_EOF;

            }

        }

        if (s->skip_map_chunk_size) {

            pkt->pos = s->skip_map_chunk_offset;

            avio_seek(pb, s->skip_map_chunk_offset, SEEK_SET);

            s->skip_map_chunk_offset = 0;

            if (avio_read(pb, pkt->data + 8 + s->video_chunk_size + s->decode_map_chunk_size,

                s->skip_map_chunk_size) != s->skip_map_chunk_size) {

                return CHUNK_EOF;

            }

        }

        s->video_chunk_size = 0;

        s->decode_map_chunk_size = 0;

        s->skip_map_chunk_size = 0;

        pkt->stream_index = s->video_stream_index;

        pkt->pts = s->video_pts;

        av_log(s->avf, AV_LOG_TRACE, "sending video frame with pts %"PRId64"\n", pkt->pts);

        s->video_pts += s->frame_pts_inc;

        chunk_type = CHUNK_HAVE_PACKET;

    } else {

        avio_seek(pb, s->next_chunk_offset, SEEK_SET);

        chunk_type = CHUNK_DONE;

    }

    return chunk_type;

}

static int init_audio(AVFormatContext *s)

{

    IPMVEContext *ipmovie = s->priv_data;

    AVStream *st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    avpriv_set_pts_info(st, 32, 1, ipmovie->audio_sample_rate);

    ipmovie->audio_stream_index = st->index;

    st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;

    st->codecpar->codec_id = ipmovie->audio_type;

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

    av_channel_layout_default(&st->codecpar->ch_layout, ipmovie->audio_channels);

    st->codecpar->sample_rate = ipmovie->audio_sample_rate;

    st->codecpar->bits_per_coded_sample = ipmovie->audio_bits;

    st->codecpar->bit_rate = ipmovie->audio_channels * st->codecpar->sample_rate *

        st->codecpar->bits_per_coded_sample;

    if (st->codecpar->codec_id == AV_CODEC_ID_INTERPLAY_DPCM)

        st->codecpar->bit_rate /= 2;

    st->codecpar->block_align = ipmovie->audio_channels * st->codecpar->bits_per_coded_sample;

    return 0;

}

/* This function loads and processes a single chunk in an IP movie file.

 * It returns the type of chunk that was processed. */

static int process_ipmovie_chunk(IPMVEContext *s, AVIOContext *pb,

    AVPacket *pkt)

{

    unsigned char chunk_preamble[CHUNK_PREAMBLE_SIZE];

    int chunk_type;

    int chunk_size;

    unsigned char opcode_preamble[OPCODE_PREAMBLE_SIZE];

    unsigned char opcode_type;

    unsigned char opcode_version;

    int opcode_size;

    unsigned char scratch[1024];

    int i, j;

    int first_color, last_color;

    int audio_flags;

    unsigned char r, g, b;

    unsigned int width, height;

    /* see if there are any pending packets */

    chunk_type = load_ipmovie_packet(s, pb, pkt);

    if (chunk_type != CHUNK_DONE)

        return chunk_type;

    /* read the next chunk, wherever the file happens to be pointing */

    if (avio_feof(pb))

        return CHUNK_EOF;

    if (avio_read(pb, chunk_preamble, CHUNK_PREAMBLE_SIZE) !=

        CHUNK_PREAMBLE_SIZE)

        return CHUNK_BAD;

    chunk_size = AV_RL16(&chunk_preamble[0]);

    chunk_type = AV_RL16(&chunk_preamble[2]);

    av_log(s->avf, AV_LOG_TRACE, "chunk type 0x%04X, 0x%04X bytes: ", chunk_type, chunk_size);

    switch (chunk_type) {

    case CHUNK_INIT_AUDIO:

        av_log(s->avf, AV_LOG_TRACE, "initialize audio\n");

        break;

    case CHUNK_AUDIO_ONLY:

        av_log(s->avf, AV_LOG_TRACE, "audio only\n");

        break;

    case CHUNK_INIT_VIDEO:

        av_log(s->avf, AV_LOG_TRACE, "initialize video\n");

        break;

    case CHUNK_VIDEO:

        av_log(s->avf, AV_LOG_TRACE, "video (and audio)\n");

        break;

    case CHUNK_SHUTDOWN:

        av_log(s->avf, AV_LOG_TRACE, "shutdown\n");

        break;

    case CHUNK_END:

        av_log(s->avf, AV_LOG_TRACE, "end\n");

        break;

    default:

        av_log(s->avf, AV_LOG_TRACE, "invalid chunk\n");

        chunk_type = CHUNK_BAD;

        break;

    }

    while ((chunk_size > 0) && (chunk_type != CHUNK_BAD)) {

        /* read the next chunk, wherever the file happens to be pointing */

        if (avio_feof(pb)) {

            chunk_type = CHUNK_EOF;

            break;

        }

        if (avio_read(pb, opcode_preamble, CHUNK_PREAMBLE_SIZE) !=

            CHUNK_PREAMBLE_SIZE) {

            chunk_type = CHUNK_BAD;

            break;

        }

        opcode_size = AV_RL16(&opcode_preamble[0]);

        opcode_type = opcode_preamble[2];

        opcode_version = opcode_preamble[3];

        chunk_size -= OPCODE_PREAMBLE_SIZE;

        chunk_size -= opcode_size;

        if (chunk_size < 0) {

            av_log(s->avf, AV_LOG_TRACE, "chunk_size countdown just went negative\n");

            chunk_type = CHUNK_BAD;

            break;

        }

        av_log(s->avf, AV_LOG_TRACE, "  opcode type %02X, version %d, 0x%04X bytes: ",

                opcode_type, opcode_version, opcode_size);

        switch (opcode_type) {

        case OPCODE_END_OF_STREAM:

            av_log(s->avf, AV_LOG_TRACE, "end of stream\n");

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_END_OF_CHUNK:

            av_log(s->avf, AV_LOG_TRACE, "end of chunk\n");

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_CREATE_TIMER:

            av_log(s->avf, AV_LOG_TRACE, "create timer\n");

            if ((opcode_version > 0) || (opcode_size != 6)) {

                av_log(s->avf, AV_LOG_TRACE, "bad create_timer opcode\n");

                chunk_type = CHUNK_BAD;

                break;

            }

            if (avio_read(pb, scratch, opcode_size) !=

                opcode_size) {

                chunk_type = CHUNK_BAD;

                break;

            }

            s->frame_pts_inc = ((uint64_t)AV_RL32(&scratch[0])) * AV_RL16(&scratch[4]);

            break;

        case OPCODE_INIT_AUDIO_BUFFERS:

            av_log(s->avf, AV_LOG_TRACE, "initialize audio buffers\n");

            if (opcode_version > 1 || opcode_size > 10 || opcode_size < 6) {

                av_log(s->avf, AV_LOG_TRACE, "bad init_audio_buffers opcode\n");

                chunk_type = CHUNK_BAD;

                break;

            }

            if (avio_read(pb, scratch, opcode_size) !=

                opcode_size) {

                chunk_type = CHUNK_BAD;

                break;

            }

            s->audio_sample_rate = AV_RL16(&scratch[4]);

            audio_flags = AV_RL16(&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 = AV_CODEC_ID_INTERPLAY_DPCM;

            else if (s->audio_bits == 16)

                s->audio_type = AV_CODEC_ID_PCM_S16LE;

            else

                s->audio_type = AV_CODEC_ID_PCM_U8;

            av_log(s->avf, AV_LOG_TRACE, "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 == AV_CODEC_ID_INTERPLAY_DPCM) ?

                    "Interplay audio" : "PCM");

            break;

        case OPCODE_START_STOP_AUDIO:

            av_log(s->avf, AV_LOG_TRACE, "start/stop audio\n");

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_INIT_VIDEO_BUFFERS:

            av_log(s->avf, AV_LOG_TRACE, "initialize video buffers\n");

            if ((opcode_version > 2) || (opcode_size > 8) || opcode_size < 4

                || opcode_version == 2 && opcode_size < 8

            ) {

                av_log(s->avf, AV_LOG_TRACE, "bad init_video_buffers opcode\n");

                chunk_type = CHUNK_BAD;

                break;

            }

            if (avio_read(pb, scratch, opcode_size) !=

                opcode_size) {

                chunk_type = CHUNK_BAD;

                break;

            }

            width  = AV_RL16(&scratch[0]) * 8;

            height = AV_RL16(&scratch[2]) * 8;

            if (width != s->video_width) {

                s->video_width = width;

                s->changed++;

            }

            if (height != s->video_height) {

                s->video_height = height;

                s->changed++;

            }

            if (opcode_version < 2 || !AV_RL16(&scratch[6])) {

                s->video_bpp = 8;

            } else {

                s->video_bpp = 16;

            }

            av_log(s->avf, AV_LOG_TRACE, "video resolution: %d x %d\n",

                    s->video_width, s->video_height);

            break;

        case OPCODE_UNKNOWN_12:

        case OPCODE_UNKNOWN_13:

        case OPCODE_UNKNOWN_14:

        case OPCODE_UNKNOWN_15:

            av_log(s->avf, AV_LOG_TRACE, "unknown (but documented) opcode %02X\n", opcode_type);

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_SEND_BUFFER:

            av_log(s->avf, AV_LOG_TRACE, "send buffer\n");

            avio_skip(pb, opcode_size);

            s->send_buffer = 1;

            break;

        case OPCODE_AUDIO_FRAME:

            av_log(s->avf, AV_LOG_TRACE, "audio frame\n");

            /* log position and move on for now */

            s->audio_chunk_offset = avio_tell(pb);

            s->audio_chunk_size = opcode_size;

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_SILENCE_FRAME:

            av_log(s->avf, AV_LOG_TRACE, "silence frame\n");

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_INIT_VIDEO_MODE:

            av_log(s->avf, AV_LOG_TRACE, "initialize video mode\n");

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_CREATE_GRADIENT:

            av_log(s->avf, AV_LOG_TRACE, "create gradient\n");

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_SET_PALETTE:

            av_log(s->avf, AV_LOG_TRACE, "set palette\n");

            /* check for the logical maximum palette size

             * (3 * 256 + 4 bytes) */

            if (opcode_size > 0x304 || opcode_size < 4) {

                av_log(s->avf, AV_LOG_TRACE, "demux_ipmovie: set_palette opcode with invalid size\n");

                chunk_type = CHUNK_BAD;

                break;

            }

            if (avio_read(pb, scratch, opcode_size) != opcode_size) {

                chunk_type = CHUNK_BAD;

                break;

            }

            /* load the palette into internal data structure */

            first_color = AV_RL16(&scratch[0]);

            last_color = first_color + AV_RL16(&scratch[2]) - 1;

            /* sanity check (since they are 16 bit values) */

            if (   (first_color > 0xFF) || (last_color > 0xFF)

                || (last_color - first_color + 1)*3 + 4 > opcode_size) {

                av_log(s->avf, AV_LOG_TRACE, "demux_ipmovie: set_palette indexes 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[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b);

                s->palette[i] |= s->palette[i] >> 6 & 0x30303;

            }

            s->has_palette = 1;

            break;

        case OPCODE_SET_PALETTE_COMPRESSED:

            av_log(s->avf, AV_LOG_TRACE, "set palette compressed\n");

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_SET_SKIP_MAP:

            av_log(s->avf, AV_LOG_TRACE, "set skip map\n");

            /* log position and move on for now */

            s->skip_map_chunk_offset = avio_tell(pb);

            s->skip_map_chunk_size = opcode_size;

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_SET_DECODING_MAP:

            av_log(s->avf, AV_LOG_TRACE, "set decoding map\n");

            /* log position and move on for now */

            s->decode_map_chunk_offset = avio_tell(pb);

            s->decode_map_chunk_size = opcode_size;

            avio_skip(pb, opcode_size);

            break;

        case OPCODE_VIDEO_DATA_06:

        case OPCODE_VIDEO_DATA_10:

        case OPCODE_VIDEO_DATA_11:

            s->frame_format = opcode_type;

            av_log(s->avf, AV_LOG_TRACE, "set video data format 0x%02X\n",

                   opcode_type);

            /* log position and move on for now */

            s->video_chunk_offset = avio_tell(pb);

            s->video_chunk_size = opcode_size;

            avio_skip(pb, opcode_size);

            break;

        default:

            av_log(s->avf, AV_LOG_TRACE, "*** unknown opcode type\n");

            chunk_type = CHUNK_BAD;

            break;

        }

    }

    if (s->avf->nb_streams == 1 && s->audio_type)

        init_audio(s->avf);

    /* make a note of where the stream is sitting */

    s->next_chunk_offset = avio_tell(pb);

    return chunk_type;

}

static const char signature[] = "Interplay MVE File\x1A\0\x1A";

static int ipmovie_probe(const AVProbeData *p)

{

    const uint8_t *b = p->buf;

    const uint8_t *b_end = p->buf + p->buf_size - sizeof(signature);

    do {

        if (b[0] == signature[0] && memcmp(b, signature, sizeof(signature)) == 0)

            return AVPROBE_SCORE_MAX;

        b++;

    } while (b < b_end);

    return 0;

}

static int ipmovie_read_header(AVFormatContext *s)

{

    IPMVEContext *ipmovie = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *st;

    unsigned char chunk_preamble[CHUNK_PREAMBLE_SIZE];

    int chunk_type, i;

    uint8_t signature_buffer[sizeof(signature)];

    int ret;

    ipmovie->avf = s;

    ret = ffio_read_size(pb, signature_buffer, sizeof(signature_buffer));

    if (ret < 0)

        return ret;

    while (memcmp(signature_buffer, signature, sizeof(signature))) {

        memmove(signature_buffer, signature_buffer + 1, sizeof(signature_buffer) - 1);

        signature_buffer[sizeof(signature_buffer) - 1] = avio_r8(pb);

        if (avio_feof(pb))

            return AVERROR_EOF;

    }

    /* on the first read, this will position the stream at the first chunk */

    ipmovie->next_chunk_offset = avio_tell(pb) + 4;

    for (i = 0; i < 256; i++)

        ipmovie->palette[i] = 0xFFU << 24;

    /* process the first chunk which should be CHUNK_INIT_VIDEO */

    if (process_ipmovie_chunk(ipmovie, pb, NULL) != 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 ((ret = ffio_read_size(pb, chunk_preamble, CHUNK_PREAMBLE_SIZE)) < 0)

        return ret;

    chunk_type = AV_RL16(&chunk_preamble[2]);

    avio_seek(pb, -CHUNK_PREAMBLE_SIZE, SEEK_CUR);

    if (chunk_type == CHUNK_VIDEO)

        ipmovie->audio_type = AV_CODEC_ID_NONE;  /* no audio */

    else if (process_ipmovie_chunk(ipmovie, pb, ffformatcontext(s)->parse_pkt) != CHUNK_INIT_AUDIO) {

        return AVERROR_INVALIDDATA;

    }

    /* initialize the stream decoders */

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    avpriv_set_pts_info(st, 63, 1, 1000000);

    ipmovie->video_stream_index = st->index;

    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

    st->codecpar->codec_id = AV_CODEC_ID_INTERPLAY_VIDEO;

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

    st->codecpar->width = ipmovie->video_width;

    st->codecpar->height = ipmovie->video_height;

    st->codecpar->bits_per_coded_sample = ipmovie->video_bpp;

    if (ipmovie->audio_type) {

        return init_audio(s);

    } else

       s->ctx_flags |= AVFMTCTX_NOHEADER;

    return 0;

}

static int ipmovie_read_packet(AVFormatContext *s,

                               AVPacket *pkt)

{

    IPMVEContext *ipmovie = s->priv_data;

    AVIOContext *pb = s->pb;

    int ret;

    for (;;) {

        ret = process_ipmovie_chunk(ipmovie, pb, pkt);

        /* dispatch the first of any pending packets */

        if ((ret == CHUNK_VIDEO) || (ret == CHUNK_AUDIO_ONLY))

            ret = load_ipmovie_packet(ipmovie, pb, pkt);

        if (ret == CHUNK_BAD)

            ret = AVERROR_INVALIDDATA;

        else if (ret == CHUNK_EOF)

            ret = AVERROR_INVALIDDATA;

        else if (ret == CHUNK_NOMEM)

            ret = AVERROR(ENOMEM);

        else if (ret == CHUNK_END || ret == CHUNK_SHUTDOWN)

            ret = AVERROR_EOF;

        else if (ret == CHUNK_HAVE_PACKET)

            ret = 0;

        else if (ret == CHUNK_INIT_VIDEO || ret == CHUNK_INIT_AUDIO)

            continue;

        else

            continue;

        return ret;

    }

}

const FFInputFormat ff_ipmovie_demuxer = {

    .p.name         = "ipmovie",

    .p.long_name    = NULL_IF_CONFIG_SMALL("Interplay MVE"),

    .priv_data_size = sizeof(IPMVEContext),

    .read_probe     = ipmovie_probe,

    .read_header    = ipmovie_read_header,

    .read_packet    = ipmovie_read_packet,

};