PeerStreamer

/*

 * Deluxe Paint Animation demuxer

 * Copyright (c) 2009 Peter Ross

 *

 * This file is part of Libav.

 *

 * Libav 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.

 *

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

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

 */

/**

 * @file

 * Deluxe Paint Animation demuxer

 */

#include "libavutil/intreadwrite.h"

#include "avformat.h"

typedef struct {

    int base_record;

    unsigned int nb_records;

    int size;

} Page;

typedef struct {

    unsigned int nb_pages;    /**< total pages in file */

    unsigned int nb_records;  /**< total records in file */

    int page_table_offset;

#define MAX_PAGES  256        /**< Deluxe Paint hardcoded value */

    Page pt[MAX_PAGES];       /**< page table */

    int page;                 /**< current page (or AVERROR_xxx code) */

    int record;               /**< current record (with in page) */

} AnmDemuxContext;

#define LPF_TAG  MKTAG('L','P','F',' ')

#define ANIM_TAG MKTAG('A','N','I','M')

static int probe(AVProbeData *p)

{

    /* verify tags and video dimensions */

    if (AV_RL32(&p->buf[0])  == LPF_TAG &&

        AV_RL32(&p->buf[16]) == ANIM_TAG &&

        AV_RL16(&p->buf[20]) && AV_RL16(&p->buf[22]))

        return AVPROBE_SCORE_MAX;

    return 0;

}

/**

 * @return page containing the requested record or AVERROR_XXX

 */

static int find_record(const AnmDemuxContext *anm, int record)

{

    int i;

    if (record >= anm->nb_records)

        return AVERROR_EOF;

    for (i = 0; i < MAX_PAGES; i++) {

        const Page *p = &anm->pt[i];

        if (p->nb_records > 0 && record >= p->base_record && record < p->base_record + p->nb_records)

            return i;

    }

    return AVERROR_INVALIDDATA;

}

static int read_header(AVFormatContext *s,

                       AVFormatParameters *ap)

{

    AnmDemuxContext *anm = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *st;

    int i, ret;

    avio_skip(pb, 4); /* magic number */

    if (avio_rl16(pb) != MAX_PAGES) {

        av_log_ask_for_sample(s, "max_pages != " AV_STRINGIFY(MAX_PAGES) "\n");

        return AVERROR_INVALIDDATA;

    }

    anm->nb_pages   = avio_rl16(pb);

    anm->nb_records = avio_rl32(pb);

    avio_skip(pb, 2); /* max records per page */

    anm->page_table_offset = avio_rl16(pb);

    if (avio_rl32(pb) != ANIM_TAG)

        return AVERROR_INVALIDDATA;

    /* video stream */

    st = av_new_stream(s, 0);

    if (!st)

        return AVERROR(ENOMEM);

    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

    st->codec->codec_id   = CODEC_ID_ANM;

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

    st->codec->width      = avio_rl16(pb);

    st->codec->height     = avio_rl16(pb);

    if (avio_r8(pb) != 0)

        goto invalid;

    avio_skip(pb, 1); /* frame rate multiplier info */

    /* ignore last delta record (used for looping) */

    if (avio_r8(pb))  /* has_last_delta */

        anm->nb_records = FFMAX(anm->nb_records - 1, 0);

    avio_skip(pb, 1); /* last_delta_valid */

    if (avio_r8(pb) != 0)

        goto invalid;

    if (avio_r8(pb) != 1)

        goto invalid;

    avio_skip(pb, 1); /* other recs per frame */

    if (avio_r8(pb) != 1)

        goto invalid;

    avio_skip(pb, 32); /* record_types */

    st->nb_frames = avio_rl32(pb);

    av_set_pts_info(st, 64, 1, avio_rl16(pb));

    avio_skip(pb, 58);

    /* color cycling and palette data */

    st->codec->extradata_size = 16*8 + 4*256;

    st->codec->extradata      = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);

    if (!st->codec->extradata) {

        ret = AVERROR(ENOMEM);

        goto close_and_return;

    }

    ret = avio_read(pb, st->codec->extradata, st->codec->extradata_size);

    if (ret < 0)

        goto close_and_return;

    /* read page table */

    ret = avio_seek(pb, anm->page_table_offset, SEEK_SET);

    if (ret < 0)

        goto close_and_return;

    for (i = 0; i < MAX_PAGES; i++) {

        Page *p = &anm->pt[i];

        p->base_record = avio_rl16(pb);

        p->nb_records  = avio_rl16(pb);

        p->size        = avio_rl16(pb);

    }

    /* find page of first frame */

    anm->page = find_record(anm, 0);

    if (anm->page < 0) {

        ret = anm->page;

        goto close_and_return;

    }

    anm->record = -1;

    return 0;

invalid:

    av_log_ask_for_sample(s, NULL);

    ret = AVERROR_INVALIDDATA;

close_and_return:

    av_close_input_stream(s);

    return ret;

}

static int read_packet(AVFormatContext *s,

                       AVPacket *pkt)

{

    AnmDemuxContext *anm = s->priv_data;

    AVIOContext *pb = s->pb;

    Page *p;

    int tmp, record_size;

    if (s->pb->eof_reached)

        return AVERROR(EIO);

    if (anm->page < 0)

        return anm->page;

repeat:

    p = &anm->pt[anm->page];

    /* parse page header */

    if (anm->record < 0) {

        avio_seek(pb, anm->page_table_offset + MAX_PAGES*6 + (anm->page<<16), SEEK_SET);

        avio_skip(pb, 8 + 2*p->nb_records);

        anm->record = 0;

    }

    /* if we have fetched all records in this page, then find the

       next page and repeat */

    if (anm->record >= p->nb_records) {

        anm->page = find_record(anm, p->base_record + p->nb_records);

        if (anm->page < 0)

            return anm->page;

        anm->record = -1;

        goto repeat;

    }

    /* fetch record size */

    tmp = avio_tell(pb);

    avio_seek(pb, anm->page_table_offset + MAX_PAGES*6 + (anm->page<<16) +

              8 + anm->record * 2, SEEK_SET);

    record_size = avio_rl16(pb);

    avio_seek(pb, tmp, SEEK_SET);

    /* fetch record */

    pkt->size = av_get_packet(s->pb, pkt, record_size);

    if (pkt->size < 0)

        return pkt->size;

    if (p->base_record + anm->record == 0)

        pkt->flags |= AV_PKT_FLAG_KEY;

    anm->record++;

    return 0;

}

AVInputFormat ff_anm_demuxer = {

    "anm",

    NULL_IF_CONFIG_SMALL("Deluxe Paint Animation"),

    sizeof(AnmDemuxContext),

    probe,

    read_header,

    read_packet,

};