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ffmpeg / libavformat / dxa.c @ b7effd4e

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/*
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 * DXA demuxer
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 * Copyright (c) 2007 Konstantin Shishkov
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "libavutil/intreadwrite.h"
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#include "avformat.h"
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#include "riff.h"
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#define DXA_EXTRA_SIZE  9
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typedef struct{
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    int frames;
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    int has_sound;
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    int bpc;
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    uint32_t bytes_left;
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    int64_t wavpos, vidpos;
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    int readvid;
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}DXAContext;
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static int dxa_probe(AVProbeData *p)
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{
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    int w, h;
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    if (p->buf_size < 15)
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        return 0;
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    w = AV_RB16(p->buf + 11);
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    h = AV_RB16(p->buf + 13);
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    /* check file header */
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    if (p->buf[0] == 'D' && p->buf[1] == 'E' &&
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        p->buf[2] == 'X' && p->buf[3] == 'A' &&
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        w && w <= 2048 && h && h <= 2048)
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        return AVPROBE_SCORE_MAX;
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    else
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        return 0;
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}
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static int dxa_read_header(AVFormatContext *s, AVFormatParameters *ap)
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{
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    AVIOContext *pb = s->pb;
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    DXAContext *c = s->priv_data;
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    AVStream *st, *ast;
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    uint32_t tag;
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    int32_t fps;
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    int w, h;
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    int num, den;
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    int flags;
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    tag = avio_rl32(pb);
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    if (tag != MKTAG('D', 'E', 'X', 'A'))
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        return -1;
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    flags = avio_r8(pb);
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    c->frames = avio_rb16(pb);
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    if(!c->frames){
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        av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");
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        return -1;
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    }
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    fps = avio_rb32(pb);
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    if(fps > 0){
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        den = 1000;
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        num = fps;
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    }else if (fps < 0){
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        den = 100000;
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        num = -fps;
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    }else{
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        den = 10;
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        num = 1;
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    }
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    w = avio_rb16(pb);
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    h = avio_rb16(pb);
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    c->has_sound = 0;
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    st = av_new_stream(s, 0);
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    if (!st)
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        return -1;
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    // Parse WAV data header
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    if(avio_rl32(pb) == MKTAG('W', 'A', 'V', 'E')){
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        uint32_t size, fsize;
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        c->has_sound = 1;
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        size = avio_rb32(pb);
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        c->vidpos = url_ftell(pb) + size;
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        url_fskip(pb, 16);
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        fsize = avio_rl32(pb);
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        ast = av_new_stream(s, 0);
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        if (!ast)
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            return -1;
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        ff_get_wav_header(pb, ast->codec, fsize);
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        // find 'data' chunk
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        while(url_ftell(pb) < c->vidpos && !url_feof(pb)){
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            tag = avio_rl32(pb);
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            fsize = avio_rl32(pb);
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            if(tag == MKTAG('d', 'a', 't', 'a')) break;
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            url_fskip(pb, fsize);
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        }
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        c->bpc = (fsize + c->frames - 1) / c->frames;
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        if(ast->codec->block_align)
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            c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align;
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        c->bytes_left = fsize;
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        c->wavpos = url_ftell(pb);
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        url_fseek(pb, c->vidpos, SEEK_SET);
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    }
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    /* now we are ready: build format streams */
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    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
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    st->codec->codec_id   = CODEC_ID_DXA;
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    st->codec->width      = w;
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    st->codec->height     = h;
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    av_reduce(&den, &num, den, num, (1UL<<31)-1);
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    av_set_pts_info(st, 33, num, den);
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    /* flags & 0x80 means that image is interlaced,
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     * flags & 0x40 means that image has double height
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     * either way set true height
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     */
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    if(flags & 0xC0){
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        st->codec->height >>= 1;
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    }
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    c->readvid = !c->has_sound;
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    c->vidpos  = url_ftell(pb);
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    s->start_time = 0;
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    s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;
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    av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
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    return 0;
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}
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static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
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{
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    DXAContext *c = s->priv_data;
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    int ret;
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    uint32_t size;
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    uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
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    int pal_size = 0;
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    if(!c->readvid && c->has_sound && c->bytes_left){
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        c->readvid = 1;
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        url_fseek(s->pb, c->wavpos, SEEK_SET);
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        size = FFMIN(c->bytes_left, c->bpc);
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        ret = av_get_packet(s->pb, pkt, size);
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        pkt->stream_index = 1;
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        if(ret != size)
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            return AVERROR(EIO);
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        c->bytes_left -= size;
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        c->wavpos = url_ftell(s->pb);
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        return 0;
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    }
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    url_fseek(s->pb, c->vidpos, SEEK_SET);
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    while(!url_feof(s->pb) && c->frames){
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        avio_read(s->pb, buf, 4);
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        switch(AV_RL32(buf)){
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        case MKTAG('N', 'U', 'L', 'L'):
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            if(av_new_packet(pkt, 4 + pal_size) < 0)
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                return AVERROR(ENOMEM);
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            pkt->stream_index = 0;
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            if(pal_size) memcpy(pkt->data, pal, pal_size);
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            memcpy(pkt->data + pal_size, buf, 4);
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            c->frames--;
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            c->vidpos = url_ftell(s->pb);
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            c->readvid = 0;
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            return 0;
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        case MKTAG('C', 'M', 'A', 'P'):
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            pal_size = 768+4;
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            memcpy(pal, buf, 4);
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            avio_read(s->pb, pal + 4, 768);
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            break;
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        case MKTAG('F', 'R', 'A', 'M'):
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            avio_read(s->pb, buf + 4, DXA_EXTRA_SIZE - 4);
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            size = AV_RB32(buf + 5);
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            if(size > 0xFFFFFF){
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                av_log(s, AV_LOG_ERROR, "Frame size is too big: %d\n", size);
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                return -1;
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            }
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            if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0)
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                return AVERROR(ENOMEM);
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            memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);
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            ret = avio_read(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);
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            if(ret != size){
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                av_free_packet(pkt);
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                return AVERROR(EIO);
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            }
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            if(pal_size) memcpy(pkt->data, pal, pal_size);
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            pkt->stream_index = 0;
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            c->frames--;
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            c->vidpos = url_ftell(s->pb);
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            c->readvid = 0;
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            return 0;
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        default:
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            av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]);
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            return -1;
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        }
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    }
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    return AVERROR(EIO);
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}
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AVInputFormat ff_dxa_demuxer = {
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    "dxa",
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    NULL_IF_CONFIG_SMALL("DXA"),
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    sizeof(DXAContext),
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    dxa_probe,
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    dxa_read_header,
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    dxa_read_packet,
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};