[libav.git] / libavformat / avidec.c

/*
 * AVI decoder.
 * Copyright (c) 2001 Fabrice Bellard.
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include "avformat.h"
#include "avi.h"
#include "dv.h"

//#define DEBUG
//#define DEBUG_SEEK

typedef struct AVIIndexEntry {
    unsigned int flags;
    unsigned int pos;
    unsigned int cum_len; /* sum of all lengths before this packet */
} AVIIndexEntry;

typedef struct AVIStream {
    AVIIndexEntry *index_entries;
    int nb_index_entries;
    int index_entries_allocated_size;
    int frame_offset; /* current frame (video) or byte (audio) counter
                         (used to compute the pts) */
    int scale;
    int rate;    
    int sample_size; /* audio only data */
    int start;
    
    int new_frame_offset; /* temporary storage (used during seek) */
    int cum_len; /* temporary storage (used during seek) */
} AVIStream;

typedef struct {
    int64_t  riff_end;
    int64_t  movi_end;
    offset_t movi_list;
    int index_loaded;
    DVDemuxContext* dv_demux;
} AVIContext;

#ifdef DEBUG
static void print_tag(const char *str, unsigned int tag, int size)
{
    printf("%s: tag=%c%c%c%c size=0x%x\n",
           str, tag & 0xff,
           (tag >> 8) & 0xff,
           (tag >> 16) & 0xff,
           (tag >> 24) & 0xff,
           size);
}
#endif

static int get_riff(AVIContext *avi, ByteIOContext *pb)
{
    uint32_t tag; 
    /* check RIFF header */
    tag = get_le32(pb);

    if (tag != MKTAG('R', 'I', 'F', 'F'))
        return -1;
    avi->riff_end = get_le32(pb);   /* RIFF chunk size */
    avi->riff_end += url_ftell(pb); /* RIFF chunk end */
    tag = get_le32(pb);
    if (tag != MKTAG('A', 'V', 'I', ' ') && tag != MKTAG('A', 'V', 'I', 'X'))
        return -1;
    
    return 0;
}

static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
    AVIContext *avi = s->priv_data;
    ByteIOContext *pb = &s->pb;
    uint32_t tag, tag1, handler;
    int codec_type, stream_index, frame_period, bit_rate, scale, rate;
    unsigned int size, nb_frames;
    int i, n;
    AVStream *st;
    AVIStream *ast;
    int xan_video = 0;  /* hack to support Xan A/V */

    if (get_riff(avi, pb) < 0)
        return -1;

    /* first list tag */
    stream_index = -1;
    codec_type = -1;
    frame_period = 0;
    for(;;) {
        if (url_feof(pb))
            goto fail;
        tag = get_le32(pb);
        size = get_le32(pb);
#ifdef DEBUG
        print_tag("tag", tag, size);
#endif

        switch(tag) {
        case MKTAG('L', 'I', 'S', 'T'):
            /* ignored, except when start of video packets */
            tag1 = get_le32(pb);
#ifdef DEBUG
            print_tag("list", tag1, 0);
#endif
            if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
                avi->movi_list = url_ftell(pb) - 4;
                avi->movi_end = avi->movi_list + size;
#ifdef DEBUG
                printf("movi end=%Lx\n", avi->movi_end);
#endif
                goto end_of_header;
            }
            break;
        case MKTAG('a', 'v', 'i', 'h'):
	    /* avi header */
            /* using frame_period is bad idea */
            frame_period = get_le32(pb);
            bit_rate = get_le32(pb) * 8;
	    url_fskip(pb, 4 * 4);
            n = get_le32(pb);
            for(i=0;i<n;i++) {
                AVIStream *ast;
                st = av_new_stream(s, i);
                if (!st)
                    goto fail;

                ast = av_mallocz(sizeof(AVIStream));
                if (!ast)
                    goto fail;
                st->priv_data = ast;
	    }
            url_fskip(pb, size - 7 * 4);
            break;
        case MKTAG('s', 't', 'r', 'h'):
            /* stream header */
            stream_index++;
            tag1 = get_le32(pb);
            handler = get_le32(pb); /* codec tag */
            switch(tag1) {
            case MKTAG('i', 'a', 'v', 's'):
	    case MKTAG('i', 'v', 'a', 's'):
                /* 
	         * After some consideration -- I don't think we 
	         * have to support anything but DV in a type1 AVIs.
	         */
	        if (s->nb_streams != 1)
		    goto fail;
	        
		if (handler != MKTAG('d', 'v', 's', 'd') &&
	            handler != MKTAG('d', 'v', 'h', 'd') &&
		    handler != MKTAG('d', 'v', 's', 'l'))
	           goto fail;
                
		av_freep(&s->streams[0]->codec.extradata);
		av_freep(&s->streams[0]);
		s->nb_streams = 0;
	        avi->dv_demux = dv_init_demux(s);
		if (!avi->dv_demux)
		    goto fail;
	        stream_index = s->nb_streams - 1;
		url_fskip(pb, size - 8);
		break;
	    case MKTAG('v', 'i', 'd', 's'):
                codec_type = CODEC_TYPE_VIDEO;

                if (stream_index >= s->nb_streams) {
                    url_fskip(pb, size - 8);
                    break;
                } 

                st = s->streams[stream_index];
                ast = st->priv_data;
                st->codec.stream_codec_tag= handler;
                
                get_le32(pb); /* flags */
                get_le16(pb); /* priority */
                get_le16(pb); /* language */
                get_le32(pb); /* XXX: initial frame ? */
                scale = get_le32(pb); /* scale */
                rate = get_le32(pb); /* rate */

                if(scale && rate){
                }else if(frame_period){
                    rate = 1000000;
                    scale = frame_period;
                }else{
                    rate = 25;
                    scale = 1;
                }
                ast->rate = rate;
                ast->scale = scale;
                av_set_pts_info(st, 64, scale, rate);
                st->codec.frame_rate = rate;
                st->codec.frame_rate_base = scale;
                get_le32(pb); /* start */
                nb_frames = get_le32(pb);
                st->start_time = 0;
                st->duration = av_rescale(nb_frames,
                    st->codec.frame_rate_base * AV_TIME_BASE,
                    st->codec.frame_rate);
		url_fskip(pb, size - 9 * 4);
                break;
            case MKTAG('a', 'u', 'd', 's'):
                {
                    unsigned int length;

                    codec_type = CODEC_TYPE_AUDIO;

                    if (stream_index >= s->nb_streams) {
                        url_fskip(pb, size - 8);
                        break;
                    } 
                    st = s->streams[stream_index];
                    ast = st->priv_data;
                    
                    get_le32(pb); /* flags */
                    get_le16(pb); /* priority */
                    get_le16(pb); /* language */
                    get_le32(pb); /* initial frame */
                    ast->scale = get_le32(pb); /* scale */
                    ast->rate = get_le32(pb);
                    av_set_pts_info(st, 64, ast->scale, ast->rate);
                    ast->start= get_le32(pb); /* start */
                    length = get_le32(pb); /* length, in samples or bytes */
                    get_le32(pb); /* buffer size */
                    get_le32(pb); /* quality */
                    ast->sample_size = get_le32(pb); /* sample ssize */
//av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d\n", ast->scale, ast->rate, ast->sample_size, ast->start);
                    st->start_time = 0;
                    if (ast->rate != 0)
                        st->duration = (int64_t)length * AV_TIME_BASE / ast->rate;
                    url_fskip(pb, size - 12 * 4);
                }
                break;
            default:
                goto fail;
            }
            break;
        case MKTAG('s', 't', 'r', 'f'):
            /* stream header */
            if (stream_index >= s->nb_streams || avi->dv_demux) {
                url_fskip(pb, size);
            } else {
                st = s->streams[stream_index];
                switch(codec_type) {
                case CODEC_TYPE_VIDEO:
                    get_le32(pb); /* size */
                    st->codec.width = get_le32(pb);
                    st->codec.height = get_le32(pb);
                    get_le16(pb); /* panes */
                    st->codec.bits_per_sample= get_le16(pb); /* depth */
                    tag1 = get_le32(pb);
                    get_le32(pb); /* ImageSize */
                    get_le32(pb); /* XPelsPerMeter */
                    get_le32(pb); /* YPelsPerMeter */
                    get_le32(pb); /* ClrUsed */
                    get_le32(pb); /* ClrImportant */

                    st->codec.extradata_size= size - 10*4;
                    st->codec.extradata= av_malloc(st->codec.extradata_size);
                    get_buffer(pb, st->codec.extradata, st->codec.extradata_size);
                    
                    if(st->codec.extradata_size & 1) //FIXME check if the encoder really did this correctly
                        get_byte(pb);

                    /* Extract palette from extradata if bpp <= 8 */
                    /* This code assumes that extradata contains only palette */
                    /* This is true for all paletted codecs implemented in ffmpeg */
                    if (st->codec.extradata_size && (st->codec.bits_per_sample <= 8)) {
                        st->codec.palctrl = av_mallocz(sizeof(AVPaletteControl));
#ifdef WORDS_BIGENDIAN
                        for (i = 0; i < FFMIN(st->codec.extradata_size, AVPALETTE_SIZE)/4; i++)
                            st->codec.palctrl->palette[i] = bswap_32(((uint32_t*)st->codec.extradata)[i]);
#else
                        memcpy(st->codec.palctrl->palette, st->codec.extradata,
                               FFMIN(st->codec.extradata_size, AVPALETTE_SIZE));
#endif
                        st->codec.palctrl->palette_changed = 1;
                    }

#ifdef DEBUG
                    print_tag("video", tag1, 0);
#endif
                    st->codec.codec_type = CODEC_TYPE_VIDEO;
                    st->codec.codec_tag = tag1;
                    st->codec.codec_id = codec_get_id(codec_bmp_tags, tag1);
                    if (st->codec.codec_id == CODEC_ID_XAN_WC4)
                        xan_video = 1;
//                    url_fskip(pb, size - 5 * 4);
                    break;
                case CODEC_TYPE_AUDIO:
                    get_wav_header(pb, &st->codec, size);
                    if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
                        url_fskip(pb, 1);
                    /* special case time: To support Xan DPCM, hardcode
                     * the format if Xxan is the video codec */
                    st->need_parsing = 1;
                    /* force parsing as several audio frames can be in
                       one packet */
                    if (xan_video)
                        st->codec.codec_id = CODEC_ID_XAN_DPCM;
                    break;
                default:
                    url_fskip(pb, size);
                    break;
                }
            }
            break;
        default:
            /* skip tag */
            size += (size & 1);
            url_fskip(pb, size);
            break;
        }
    }
 end_of_header:
    /* check stream number */
    if (stream_index != s->nb_streams - 1) {
    fail:
        for(i=0;i<s->nb_streams;i++) {
            av_freep(&s->streams[i]->codec.extradata);
            av_freep(&s->streams[i]);
        }
        return -1;
    }

    return 0;
}

static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    AVIContext *avi = s->priv_data;
    ByteIOContext *pb = &s->pb;
    int n, d[8], size, i;
    void* dstr;

    memset(d, -1, sizeof(int)*8);
   
    if (avi->dv_demux) {
        size = dv_get_packet(avi->dv_demux, pkt);
	if (size >= 0)
	    return size;
    }
        
    for(i=url_ftell(pb); !url_feof(pb); i++) {
        int j;

	if (i >= avi->movi_end) { /* Let's see if it's an OpenDML AVI */
	    uint32_t tag, size, tag2;
	    url_fskip(pb, avi->riff_end - url_ftell(pb));
	    if (get_riff(avi, pb) < 0)
	        return -1;
	    
	    tag = get_le32(pb);
	    size = get_le32(pb);
	    tag2 = get_le32(pb);
	    if (tag == MKTAG('L','I','S','T') && tag2 == MKTAG('m','o','v','i'))
	        avi->movi_end = url_ftell(pb) + size - 4; 
	    else
	        return -1;
	}

        for(j=0; j<7; j++)
            d[j]= d[j+1];
        d[7]= get_byte(pb);
        
        size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
        
        //parse ix##
        n= (d[2] - '0') * 10 + (d[3] - '0');
        if(    d[2] >= '0' && d[2] <= '9'
            && d[3] >= '0' && d[3] <= '9'
            && d[0] == 'i' && d[1] == 'x'
            && n < s->nb_streams
            && i + size <= avi->movi_end){
            
            url_fskip(pb, size);
        }
        
        //parse ##dc/##wb
        n= (d[0] - '0') * 10 + (d[1] - '0');
        if(    d[0] >= '0' && d[0] <= '9'
            && d[1] >= '0' && d[1] <= '9'
            && ((d[2] == 'd' && d[3] == 'c') || 
	        (d[2] == 'w' && d[3] == 'b') || 
		(d[2] == 'd' && d[3] == 'b') ||
		(d[2] == '_' && d[3] == '_'))
            && n < s->nb_streams
            && i + size <= avi->movi_end) {
        
            av_new_packet(pkt, size);
            get_buffer(pb, pkt->data, size);
            if (size & 1) {
                get_byte(pb);
		size++;
	    }
	
	    if (avi->dv_demux) {
	        dstr = pkt->destruct;
	        size = dv_produce_packet(avi->dv_demux, pkt,
		                         pkt->data, pkt->size);
		pkt->destruct = dstr;
                pkt->flags |= PKT_FLAG_KEY;
	    } else {
                AVStream *st;
                AVIStream *ast;
                st = s->streams[n];
                ast = st->priv_data;

                /* XXX: how to handle B frames in avi ? */
                pkt->pts = ast->frame_offset;
                if(ast->sample_size)
                    pkt->pts /= ast->sample_size;
//printf("%Ld %d %d %d %d\n", pkt->pts, ast->frame_offset, ast->scale,  AV_TIME_BASE,  ast->rate);
                pkt->stream_index = n;
                /* FIXME: We really should read index for that */
                if (st->codec.codec_type == CODEC_TYPE_VIDEO) {
                    if (ast->frame_offset < ast->nb_index_entries) {
                        if (ast->index_entries[ast->frame_offset].flags & AVIIF_INDEX)
                            pkt->flags |= PKT_FLAG_KEY; 
                    } else {
                        /* if no index, better to say that all frames
                           are key frames */
                        pkt->flags |= PKT_FLAG_KEY;
                    }
                } else {
                    pkt->flags |= PKT_FLAG_KEY; 
                }
                if(ast->sample_size)
                    ast->frame_offset += pkt->size;
                else
                    ast->frame_offset++;
	    }
            return size;
        }
    }
    return -1;
}

/* XXX: we make the implicit supposition that the position are sorted
   for each stream */
static int avi_read_idx1(AVFormatContext *s, int size)
{
    ByteIOContext *pb = &s->pb;
    int nb_index_entries, i;
    AVStream *st;
    AVIStream *ast;
    AVIIndexEntry *ie, *entries;
    unsigned int index, tag, flags, pos, len;
    
    nb_index_entries = size / 16;
    if (nb_index_entries <= 0)
        return -1;

    /* read the entries and sort them in each stream component */
    for(i = 0; i < nb_index_entries; i++) {
        tag = get_le32(pb);
        flags = get_le32(pb);
        pos = get_le32(pb);
        len = get_le32(pb);
#if defined(DEBUG_SEEK) && 0
        printf("%d: tag=0x%x flags=0x%x pos=0x%x len=%d\n", 
               i, tag, flags, pos, len);
#endif
        index = ((tag & 0xff) - '0') * 10;
        index += ((tag >> 8) & 0xff) - '0';
        if (index >= s->nb_streams)
            continue;
        st = s->streams[index];
        ast = st->priv_data;
        
        entries = av_fast_realloc(ast->index_entries,
                                  &ast->index_entries_allocated_size,
                                  (ast->nb_index_entries + 1) * 
                                  sizeof(AVIIndexEntry));
        if (entries) {
            ast->index_entries = entries;
            ie = &entries[ast->nb_index_entries++];
            ie->flags = flags;
            ie->pos = pos;
            ie->cum_len = ast->cum_len;
            ast->cum_len += len;
        }
    }
    return 0;
}

static int avi_load_index(AVFormatContext *s)
{
    AVIContext *avi = s->priv_data;
    ByteIOContext *pb = &s->pb;
    uint32_t tag, size;
    offset_t pos= url_ftell(pb);
    
    url_fseek(pb, avi->movi_end, SEEK_SET);
#ifdef DEBUG_SEEK
    printf("movi_end=0x%llx\n", avi->movi_end);
#endif
    for(;;) {
        if (url_feof(pb))
            break;
        tag = get_le32(pb);
        size = get_le32(pb);
#ifdef DEBUG_SEEK
        printf("tag=%c%c%c%c size=0x%x\n",
               tag & 0xff,
               (tag >> 8) & 0xff,
               (tag >> 16) & 0xff,
               (tag >> 24) & 0xff,
               size);
#endif
        switch(tag) {
        case MKTAG('i', 'd', 'x', '1'):
            if (avi_read_idx1(s, size) < 0)
                goto skip;
            else
                goto the_end;
            break;
        default:
        skip:
            size += (size & 1);
            url_fskip(pb, size);
            break;
        }
    }
 the_end:
    url_fseek(pb, pos, SEEK_SET);
    return 0;
}

/* return the index entry whose position is immediately >= 'wanted_pos' */
static int locate_frame_in_index(AVIIndexEntry *entries, 
                                 int nb_entries, int wanted_pos)
{
    int a, b, m, pos;
    
    a = 0;
    b = nb_entries - 1;
    while (a <= b) {
        m = (a + b) >> 1;
        pos = entries[m].pos;
        if (pos == wanted_pos)
            goto found;
        else if (pos > wanted_pos) {
            b = m - 1;
        } else {
            a = m + 1;
        }
    }
    m = a;
    if (m > 0)
        m--;
 found:
    return m;
}

static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp)
{
    AVIContext *avi = s->priv_data;
    AVStream *st;
    AVIStream *ast;
    int frame_number, i;
    int64_t pos;

    if (!avi->index_loaded) {
        /* we only load the index on demand */
        avi_load_index(s);
        avi->index_loaded = 1;
    }
    if (stream_index < 0) {
        for(i = 0; i < s->nb_streams; i++) {
            st = s->streams[i];
            if (st->codec.codec_type == CODEC_TYPE_VIDEO)
                goto found;
        }
        return -1;
    found:
        stream_index = i;
    }

    st = s->streams[stream_index];
    if (st->codec.codec_type != CODEC_TYPE_VIDEO)
        return -1;
    ast = st->priv_data;
    /* compute the frame number */
    frame_number = timestamp;
#ifdef DEBUG_SEEK
    printf("timestamp=%0.3f nb_indexes=%d frame_number=%d\n", 
           (double)timestamp / AV_TIME_BASE,
           ast->nb_index_entries, frame_number);
#endif
    /* find a closest key frame before */
    if (frame_number >= ast->nb_index_entries)
        return -1;
    while (frame_number >= 0 &&
           !(ast->index_entries[frame_number].flags & AVIIF_INDEX))
        frame_number--;
    if (frame_number < 0)
        return -1;
    ast->new_frame_offset = frame_number;

    /* find the position */
    pos = ast->index_entries[frame_number].pos;

#ifdef DEBUG_SEEK
    printf("key_frame_number=%d pos=0x%llx\n", 
           frame_number, pos);
#endif
    
    /* update the frame counters for all the other stream by looking
       at the positions just after the one found */
    for(i = 0; i < s->nb_streams; i++) {
        int j;
        if (i != stream_index) {
            st = s->streams[i];
            ast = st->priv_data;
            if (ast->nb_index_entries <= 0)
                return -1;
            j = locate_frame_in_index(ast->index_entries,
                                      ast->nb_index_entries,
                                      pos);
            /* get next frame */
            if ((j  + 1) < ast->nb_index_entries)
                j++;
            /* extract the current frame number */
            if (ast->sample_size==0)
                ast->new_frame_offset = j;
            else
                ast->new_frame_offset = ast->index_entries[j].cum_len;
        }
    }
    
    /* everything is OK now. We can update the frame offsets */
    for(i = 0; i < s->nb_streams; i++) {
        st = s->streams[i];
        ast = st->priv_data;
        ast->frame_offset = ast->new_frame_offset;
#ifdef DEBUG_SEEK
        printf("%d: frame_offset=%d\n", i, 
               ast->frame_offset);
#endif
    }
    /* do the seek */
    pos += avi->movi_list;
    url_fseek(&s->pb, pos, SEEK_SET);
    return 0;
}

static int avi_read_close(AVFormatContext *s)
{
    int i;
    AVIContext *avi = s->priv_data;

    for(i=0;i<s->nb_streams;i++) {
        AVStream *st = s->streams[i];
        AVIStream *ast = st->priv_data;
        if(ast){
            av_free(ast->index_entries);
            av_free(ast);
        }
        av_free(st->codec.extradata);
        av_free(st->codec.palctrl);
    }

    if (avi->dv_demux)
        av_free(avi->dv_demux);

    return 0;
}

static int avi_probe(AVProbeData *p)
{
    /* check file header */
    if (p->buf_size <= 32)
        return 0;
    if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
        p->buf[2] == 'F' && p->buf[3] == 'F' &&
        p->buf[8] == 'A' && p->buf[9] == 'V' &&
        p->buf[10] == 'I' && p->buf[11] == ' ')
        return AVPROBE_SCORE_MAX;
    else
        return 0;
}

static AVInputFormat avi_iformat = {
    "avi",
    "avi format",
    sizeof(AVIContext),
    avi_probe,
    avi_read_header,
    avi_read_packet,
    avi_read_close,
    avi_read_seek,
};

int avidec_init(void)
{
    av_register_input_format(&avi_iformat);
    return 0;
}
Commit	Line	Data
de6d9b64 FB	1	/*
de6d9b64 FB	2	* AVI decoder.
19720f15	3	* Copyright (c) 2001 Fabrice Bellard.
de6d9b64	4	*
19720f15 FB	5	* This library is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU Lesser General Public
	7	* License as published by the Free Software Foundation; either
	8	* version 2 of the License, or (at your option) any later version.
de6d9b64	9	*
19720f15	10	* This library is distributed in the hope that it will be useful,
de6d9b64	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
19720f15 FB	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19720f15 FB	13	* Lesser General Public License for more details.
de6d9b64	14	*
19720f15 FB	15	* You should have received a copy of the GNU Lesser General Public
	16	* License along with this library; if not, write to the Free Software
	17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
de6d9b64	18	*/
de6d9b64 FB	19	#include "avformat.h"
de6d9b64 FB	20	#include "avi.h"
7458ccbb	21	#include "dv.h"
de6d9b64 FB	22
de6d9b64 FB	23	//#define DEBUG
155e9ee9 FB	24	//#define DEBUG_SEEK
	25
	26	typedef struct AVIIndexEntry {
	27	unsigned int flags;
	28	unsigned int pos;
	29	unsigned int cum_len; /* sum of all lengths before this packet */
	30	} AVIIndexEntry;
	31
	32	typedef struct AVIStream {
	33	AVIIndexEntry *index_entries;
	34	int nb_index_entries;
	35	int index_entries_allocated_size;
	36	int frame_offset; /* current frame (video) or byte (audio) counter
	37	(used to compute the pts) */
	38	int scale;
	39	int rate;
	40	int sample_size; /* audio only data */
1fa3d65d	41	int start;
155e9ee9 FB	42
	43	int new_frame_offset; /* temporary storage (used during seek) */
	44	int cum_len; /* temporary storage (used during seek) */
	45	} AVIStream;
de6d9b64 FB	46
de6d9b64 FB	47	typedef struct {
7458ccbb RS	48	int64_t riff_end;
7458ccbb RS	49	int64_t movi_end;
de6d9b64	50	offset_t movi_list;
155e9ee9	51	int index_loaded;
ddaae6a9	52	DVDemuxContext* dv_demux;
de6d9b64 FB	53	} AVIContext;
	54
	55	#ifdef DEBUG
1101abfe	56	static void print_tag(const char *str, unsigned int tag, int size)
de6d9b64 FB	57	{
	58	printf("%s: tag=%c%c%c%c size=0x%x\n",
	59	str, tag & 0xff,
	60	(tag >> 8) & 0xff,
	61	(tag >> 16) & 0xff,
	62	(tag >> 24) & 0xff,
	63	size);
	64	}
	65	#endif
	66
06219cb1 RS	67	static int get_riff(AVIContext avi, ByteIOContext pb)
	68	{
	69	uint32_t tag;
	70	/* check RIFF header */
	71	tag = get_le32(pb);
	72
	73	if (tag != MKTAG('R', 'I', 'F', 'F'))
	74	return -1;
	75	avi->riff_end = get_le32(pb); /* RIFF chunk size */
	76	avi->riff_end += url_ftell(pb); /* RIFF chunk end */
	77	tag = get_le32(pb);
	78	if (tag != MKTAG('A', 'V', 'I', ' ') && tag != MKTAG('A', 'V', 'I', 'X'))
	79	return -1;
	80
	81	return 0;
	82	}
	83
1101abfe	84	static int avi_read_header(AVFormatContext s, AVFormatParameters ap)
de6d9b64	85	{
c9a65ca8	86	AVIContext *avi = s->priv_data;
de6d9b64	87	ByteIOContext *pb = &s->pb;
deb0a292	88	uint32_t tag, tag1, handler;
b559b29b	89	int codec_type, stream_index, frame_period, bit_rate, scale, rate;
247eadca FB	90	unsigned int size, nb_frames;
247eadca FB	91	int i, n;
de6d9b64	92	AVStream *st;
155e9ee9	93	AVIStream *ast;
9e8cd0db	94	int xan_video = 0; /* hack to support Xan A/V */
de6d9b64	95
06219cb1	96	if (get_riff(avi, pb) < 0)
de6d9b64	97	return -1;
1101abfe	98
de6d9b64 FB	99	/* first list tag */
	100	stream_index = -1;
	101	codec_type = -1;
	102	frame_period = 0;
	103	for(;;) {
	104	if (url_feof(pb))
	105	goto fail;
	106	tag = get_le32(pb);
	107	size = get_le32(pb);
	108	#ifdef DEBUG
	109	print_tag("tag", tag, size);
	110	#endif
	111
	112	switch(tag) {
	113	case MKTAG('L', 'I', 'S', 'T'):
	114	/* ignored, except when start of video packets */
	115	tag1 = get_le32(pb);
	116	#ifdef DEBUG
	117	print_tag("list", tag1, 0);
	118	#endif
	119	if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
155e9ee9 FB	120	avi->movi_list = url_ftell(pb) - 4;
155e9ee9 FB	121	avi->movi_end = avi->movi_list + size;
de6d9b64 FB	122	#ifdef DEBUG
	123	printf("movi end=%Lx\n", avi->movi_end);
	124	#endif
	125	goto end_of_header;
	126	}
	127	break;
	128	case MKTAG('a', 'v', 'i', 'h'):
1101abfe ZK	129	/* avi header */
1101abfe ZK	130	/* using frame_period is bad idea */
de6d9b64 FB	131	frame_period = get_le32(pb);
de6d9b64 FB	132	bit_rate = get_le32(pb) * 8;
1101abfe	133	url_fskip(pb, 4 * 4);
247eadca FB	134	n = get_le32(pb);
247eadca FB	135	for(i=0;i<n;i++) {
155e9ee9	136	AVIStream *ast;
7458ccbb	137	st = av_new_stream(s, i);
de6d9b64 FB	138	if (!st)
de6d9b64 FB	139	goto fail;
9ee91c2f	140
155e9ee9 FB	141	ast = av_mallocz(sizeof(AVIStream));
	142	if (!ast)
	143	goto fail;
	144	st->priv_data = ast;
1101abfe	145	}
de6d9b64 FB	146	url_fskip(pb, size - 7 * 4);
	147	break;
	148	case MKTAG('s', 't', 'r', 'h'):
	149	/* stream header */
	150	stream_index++;
	151	tag1 = get_le32(pb);
7458ccbb	152	handler = get_le32(pb); /* codec tag */
de6d9b64	153	switch(tag1) {
deb0a292 RS	154	case MKTAG('i', 'a', 'v', 's'):
deb0a292 RS	155	case MKTAG('i', 'v', 'a', 's'):
7458ccbb RS	156	/*
	157	* After some consideration -- I don't think we
	158	* have to support anything but DV in a type1 AVIs.
	159	*/
deb0a292 RS	160	if (s->nb_streams != 1)
deb0a292 RS	161	goto fail;
7458ccbb RS	162
	163	if (handler != MKTAG('d', 'v', 's', 'd') &&
	164	handler != MKTAG('d', 'v', 'h', 'd') &&
	165	handler != MKTAG('d', 'v', 's', 'l'))
	166	goto fail;
ddaae6a9 RS	167
	168	av_freep(&s->streams[0]->codec.extradata);
	169	av_freep(&s->streams[0]);
	170	s->nb_streams = 0;
	171	avi->dv_demux = dv_init_demux(s);
7458ccbb RS	172	if (!avi->dv_demux)
7458ccbb RS	173	goto fail;
ddaae6a9 RS	174	stream_index = s->nb_streams - 1;
	175	url_fskip(pb, size - 8);
	176	break;
deb0a292	177	case MKTAG('v', 'i', 'd', 's'):
de6d9b64	178	codec_type = CODEC_TYPE_VIDEO;
b559b29b MN	179
b559b29b MN	180	if (stream_index >= s->nb_streams) {
7458ccbb	181	url_fskip(pb, size - 8);
b559b29b MN	182	break;
	183	}
	184
	185	st = s->streams[stream_index];
155e9ee9	186	ast = st->priv_data;
76e9d392	187	st->codec.stream_codec_tag= handler;
155e9ee9	188
de6d9b64 FB	189	get_le32(pb); /* flags */
	190	get_le16(pb); /* priority */
	191	get_le16(pb); /* language */
	192	get_le32(pb); /* XXX: initial frame ? */
deb0a292 RS	193	scale = get_le32(pb); /* scale */
deb0a292 RS	194	rate = get_le32(pb); /* rate */
b559b29b	195
14bea432	196	if(scale && rate){
14bea432	197	}else if(frame_period){
155e9ee9 FB	198	rate = 1000000;
155e9ee9 FB	199	scale = frame_period;
14bea432	200	}else{
155e9ee9 FB	201	rate = 25;
155e9ee9 FB	202	scale = 1;
14bea432	203	}
155e9ee9 FB	204	ast->rate = rate;
155e9ee9 FB	205	ast->scale = scale;
cdd5034f	206	av_set_pts_info(st, 64, scale, rate);
155e9ee9 FB	207	st->codec.frame_rate = rate;
155e9ee9 FB	208	st->codec.frame_rate_base = scale;
247eadca FB	209	get_le32(pb); /* start */
	210	nb_frames = get_le32(pb);
	211	st->start_time = 0;
cde073b4 MN	212	st->duration = av_rescale(nb_frames,
	213	st->codec.frame_rate_base * AV_TIME_BASE,
	214	st->codec.frame_rate);
247eadca	215	url_fskip(pb, size - 9 * 4);
de6d9b64 FB	216	break;
de6d9b64 FB	217	case MKTAG('a', 'u', 'd', 's'):
247eadca	218	{
155e9ee9	219	unsigned int length;
247eadca FB	220
	221	codec_type = CODEC_TYPE_AUDIO;
	222
	223	if (stream_index >= s->nb_streams) {
7458ccbb	224	url_fskip(pb, size - 8);
247eadca FB	225	break;
	226	}
	227	st = s->streams[stream_index];
155e9ee9 FB	228	ast = st->priv_data;
155e9ee9 FB	229
247eadca FB	230	get_le32(pb); /* flags */
	231	get_le16(pb); /* priority */
	232	get_le16(pb); /* language */
	233	get_le32(pb); /* initial frame */
155e9ee9 FB	234	ast->scale = get_le32(pb); /* scale */
155e9ee9 FB	235	ast->rate = get_le32(pb);
cdd5034f	236	av_set_pts_info(st, 64, ast->scale, ast->rate);
1fa3d65d	237	ast->start= get_le32(pb); /* start */
247eadca	238	length = get_le32(pb); /* length, in samples or bytes */
155e9ee9 FB	239	get_le32(pb); /* buffer size */
	240	get_le32(pb); /* quality */
	241	ast->sample_size = get_le32(pb); /* sample ssize */
1fa3d65d	242	//av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d\n", ast->scale, ast->rate, ast->sample_size, ast->start);
247eadca	243	st->start_time = 0;
cde073b4 MN	244	if (ast->rate != 0)
cde073b4 MN	245	st->duration = (int64_t)length * AV_TIME_BASE / ast->rate;
155e9ee9	246	url_fskip(pb, size - 12 * 4);
247eadca	247	}
9bf9a5fc MN	248	break;
	249	default:
	250	goto fail;
de6d9b64 FB	251	}
	252	break;
	253	case MKTAG('s', 't', 'r', 'f'):
	254	/* stream header */
7458ccbb	255	if (stream_index >= s->nb_streams \|\| avi->dv_demux) {
de6d9b64 FB	256	url_fskip(pb, size);
	257	} else {
	258	st = s->streams[stream_index];
	259	switch(codec_type) {
	260	case CODEC_TYPE_VIDEO:
	261	get_le32(pb); /* size */
	262	st->codec.width = get_le32(pb);
	263	st->codec.height = get_le32(pb);
de6d9b64	264	get_le16(pb); /* panes */
b559b29b	265	st->codec.bits_per_sample= get_le16(pb); /* depth */
de6d9b64	266	tag1 = get_le32(pb);
b559b29b MN	267	get_le32(pb); /* ImageSize */
	268	get_le32(pb); /* XPelsPerMeter */
	269	get_le32(pb); /* YPelsPerMeter */
	270	get_le32(pb); /* ClrUsed */
	271	get_le32(pb); /* ClrImportant */
	272
	273	st->codec.extradata_size= size - 10*4;
5ae2c73e	274	st->codec.extradata= av_malloc(st->codec.extradata_size);
b559b29b	275	get_buffer(pb, st->codec.extradata, st->codec.extradata_size);
952c69c4 MN	276
	277	if(st->codec.extradata_size & 1) //FIXME check if the encoder really did this correctly
	278	get_byte(pb);
b559b29b	279
5e29abf8 RT	280	/* Extract palette from extradata if bpp <= 8 */
	281	/* This code assumes that extradata contains only palette */
	282	/* This is true for all paletted codecs implemented in ffmpeg */
	283	if (st->codec.extradata_size && (st->codec.bits_per_sample <= 8)) {
	284	st->codec.palctrl = av_mallocz(sizeof(AVPaletteControl));
	285	#ifdef WORDS_BIGENDIAN
19d053c5 RS	286	for (i = 0; i < FFMIN(st->codec.extradata_size, AVPALETTE_SIZE)/4; i++)
19d053c5 RS	287	st->codec.palctrl->palette[i] = bswap_32(((uint32_t*)st->codec.extradata)[i]);
5e29abf8 RT	288	#else
	289	memcpy(st->codec.palctrl->palette, st->codec.extradata,
	290	FFMIN(st->codec.extradata_size, AVPALETTE_SIZE));
	291	#endif
	292	st->codec.palctrl->palette_changed = 1;
	293	}
	294
de6d9b64 FB	295	#ifdef DEBUG
	296	print_tag("video", tag1, 0);
	297	#endif
	298	st->codec.codec_type = CODEC_TYPE_VIDEO;
	299	st->codec.codec_tag = tag1;
	300	st->codec.codec_id = codec_get_id(codec_bmp_tags, tag1);
9e8cd0db MM	301	if (st->codec.codec_id == CODEC_ID_XAN_WC4)
9e8cd0db MM	302	xan_video = 1;
b559b29b	303	// url_fskip(pb, size - 5 * 4);
de6d9b64	304	break;
9bf9a5fc	305	case CODEC_TYPE_AUDIO:
2e7973bb	306	get_wav_header(pb, &st->codec, size);
1cef9527 FR	307	if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
1cef9527 FR	308	url_fskip(pb, 1);
9e8cd0db MM	309	/* special case time: To support Xan DPCM, hardcode
9e8cd0db MM	310	* the format if Xxan is the video codec */
155e9ee9 FB	311	st->need_parsing = 1;
	312	/* force parsing as several audio frames can be in
	313	one packet */
9e8cd0db MM	314	if (xan_video)
9e8cd0db MM	315	st->codec.codec_id = CODEC_ID_XAN_DPCM;
de6d9b64 FB	316	break;
	317	default:
	318	url_fskip(pb, size);
	319	break;
	320	}
	321	}
	322	break;
	323	default:
	324	/* skip tag */
	325	size += (size & 1);
	326	url_fskip(pb, size);
	327	break;
	328	}
	329	}
	330	end_of_header:
	331	/* check stream number */
	332	if (stream_index != s->nb_streams - 1) {
	333	fail:
	334	for(i=0;i<s->nb_streams;i++) {
8a7b1b18	335	av_freep(&s->streams[i]->codec.extradata);
9145f8b3	336	av_freep(&s->streams[i]);
de6d9b64 FB	337	}
	338	return -1;
	339	}
1101abfe	340
de6d9b64 FB	341	return 0;
	342	}
	343
1101abfe	344	static int avi_read_packet(AVFormatContext s, AVPacket pkt)
de6d9b64 FB	345	{
	346	AVIContext *avi = s->priv_data;
	347	ByteIOContext *pb = &s->pb;
df99755b	348	int n, d[8], size, i;
7458ccbb	349	void* dstr;
deb0a292	350
df99755b	351	memset(d, -1, sizeof(int)*8);
7458ccbb RS	352
	353	if (avi->dv_demux) {
	354	size = dv_get_packet(avi->dv_demux, pkt);
	355	if (size >= 0)
	356	return size;
2af7e610	357	}
7458ccbb	358
06219cb1	359	for(i=url_ftell(pb); !url_feof(pb); i++) {
df99755b	360	int j;
1101abfe	361
06219cb1 RS	362	if (i >= avi->movi_end) { /* Let's see if it's an OpenDML AVI */
	363	uint32_t tag, size, tag2;
	364	url_fskip(pb, avi->riff_end - url_ftell(pb));
	365	if (get_riff(avi, pb) < 0)
	366	return -1;
	367
	368	tag = get_le32(pb);
	369	size = get_le32(pb);
	370	tag2 = get_le32(pb);
	371	if (tag == MKTAG('L','I','S','T') && tag2 == MKTAG('m','o','v','i'))
	372	avi->movi_end = url_ftell(pb) + size - 4;
	373	else
	374	return -1;
	375	}
	376
df99755b MN	377	for(j=0; j<7; j++)
	378	d[j]= d[j+1];
	379	d[7]= get_byte(pb);
	380
	381	size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
	382
	383	//parse ix##
	384	n= (d[2] - '0') * 10 + (d[3] - '0');
	385	if( d[2] >= '0' && d[2] <= '9'
	386	&& d[3] >= '0' && d[3] <= '9'
	387	&& d[0] == 'i' && d[1] == 'x'
	388	&& n < s->nb_streams
	389	&& i + size <= avi->movi_end){
	390
	391	url_fskip(pb, size);
	392	}
	393
	394	//parse ##dc/##wb
	395	n= (d[0] - '0') * 10 + (d[1] - '0');
	396	if( d[0] >= '0' && d[0] <= '9'
	397	&& d[1] >= '0' && d[1] <= '9'
deb0a292 RS	398	&& ((d[2] == 'd' && d[3] == 'c') \|\|
	399	(d[2] == 'w' && d[3] == 'b') \|\|
	400	(d[2] == 'd' && d[3] == 'b') \|\|
	401	(d[2] == '_' && d[3] == '_'))
df99755b	402	&& n < s->nb_streams
deb0a292	403	&& i + size <= avi->movi_end) {
df99755b	404
7458ccbb	405	av_new_packet(pkt, size);
2af7e610	406	get_buffer(pb, pkt->data, size);
7458ccbb	407	if (size & 1) {
2af7e610	408	get_byte(pb);
7458ccbb RS	409	size++;
	410	}
	411
	412	if (avi->dv_demux) {
	413	dstr = pkt->destruct;
	414	size = dv_produce_packet(avi->dv_demux, pkt,
	415	pkt->data, pkt->size);
	416	pkt->destruct = dstr;
155e9ee9	417	pkt->flags \|= PKT_FLAG_KEY;
7458ccbb	418	} else {
155e9ee9 FB	419	AVStream *st;
	420	AVIStream *ast;
	421	st = s->streams[n];
	422	ast = st->priv_data;
	423
	424	/* XXX: how to handle B frames in avi ? */
cdd5034f	425	pkt->pts = ast->frame_offset;
1fa3d65d	426	if(ast->sample_size)
cdd5034f	427	pkt->pts /= ast->sample_size;
0a61ba58	428	//printf("%Ld %d %d %d %d\n", pkt->pts, ast->frame_offset, ast->scale, AV_TIME_BASE, ast->rate);
7458ccbb	429	pkt->stream_index = n;
155e9ee9 FB	430	/* FIXME: We really should read index for that */
	431	if (st->codec.codec_type == CODEC_TYPE_VIDEO) {
	432	if (ast->frame_offset < ast->nb_index_entries) {
	433	if (ast->index_entries[ast->frame_offset].flags & AVIIF_INDEX)
	434	pkt->flags \|= PKT_FLAG_KEY;
	435	} else {
	436	/* if no index, better to say that all frames
	437	are key frames */
	438	pkt->flags \|= PKT_FLAG_KEY;
	439	}
155e9ee9	440	} else {
155e9ee9 FB	441	pkt->flags \|= PKT_FLAG_KEY;
155e9ee9 FB	442	}
1fa3d65d MN	443	if(ast->sample_size)
	444	ast->frame_offset += pkt->size;
	445	else
	446	ast->frame_offset++;
7458ccbb RS	447	}
7458ccbb RS	448	return size;
df99755b MN	449	}
df99755b MN	450	}
df99755b	451	return -1;
de6d9b64 FB	452	}
de6d9b64 FB	453
155e9ee9 FB	454	/* XXX: we make the implicit supposition that the position are sorted
	455	for each stream */
	456	static int avi_read_idx1(AVFormatContext *s, int size)
	457	{
	458	ByteIOContext *pb = &s->pb;
	459	int nb_index_entries, i;
	460	AVStream *st;
	461	AVIStream *ast;
	462	AVIIndexEntry ie, entries;
	463	unsigned int index, tag, flags, pos, len;
	464
	465	nb_index_entries = size / 16;
	466	if (nb_index_entries <= 0)
	467	return -1;
	468
	469	/* read the entries and sort them in each stream component */
	470	for(i = 0; i < nb_index_entries; i++) {
	471	tag = get_le32(pb);
	472	flags = get_le32(pb);
	473	pos = get_le32(pb);
	474	len = get_le32(pb);
	475	#if defined(DEBUG_SEEK) && 0
	476	printf("%d: tag=0x%x flags=0x%x pos=0x%x len=%d\n",
	477	i, tag, flags, pos, len);
	478	#endif
	479	index = ((tag & 0xff) - '0') * 10;
	480	index += ((tag >> 8) & 0xff) - '0';
	481	if (index >= s->nb_streams)
	482	continue;
	483	st = s->streams[index];
	484	ast = st->priv_data;
	485
	486	entries = av_fast_realloc(ast->index_entries,
	487	&ast->index_entries_allocated_size,
	488	(ast->nb_index_entries + 1) *
	489	sizeof(AVIIndexEntry));
	490	if (entries) {
	491	ast->index_entries = entries;
	492	ie = &entries[ast->nb_index_entries++];
	493	ie->flags = flags;
	494	ie->pos = pos;
	495	ie->cum_len = ast->cum_len;
	496	ast->cum_len += len;
	497	}
	498	}
	499	return 0;
	500	}
	501
	502	static int avi_load_index(AVFormatContext *s)
	503	{
	504	AVIContext *avi = s->priv_data;
	505	ByteIOContext *pb = &s->pb;
	506	uint32_t tag, size;
e6c0297f MN	507	offset_t pos= url_ftell(pb);
e6c0297f MN	508
155e9ee9 FB	509	url_fseek(pb, avi->movi_end, SEEK_SET);
	510	#ifdef DEBUG_SEEK
	511	printf("movi_end=0x%llx\n", avi->movi_end);
	512	#endif
	513	for(;;) {
	514	if (url_feof(pb))
	515	break;
	516	tag = get_le32(pb);
	517	size = get_le32(pb);
	518	#ifdef DEBUG_SEEK
	519	printf("tag=%c%c%c%c size=0x%x\n",
	520	tag & 0xff,
	521	(tag >> 8) & 0xff,
	522	(tag >> 16) & 0xff,
	523	(tag >> 24) & 0xff,
	524	size);
	525	#endif
	526	switch(tag) {
	527	case MKTAG('i', 'd', 'x', '1'):
	528	if (avi_read_idx1(s, size) < 0)
	529	goto skip;
	530	else
	531	goto the_end;
	532	break;
	533	default:
	534	skip:
	535	size += (size & 1);
	536	url_fskip(pb, size);
	537	break;
	538	}
	539	}
	540	the_end:
e6c0297f	541	url_fseek(pb, pos, SEEK_SET);
155e9ee9 FB	542	return 0;
	543	}
	544
	545	/* return the index entry whose position is immediately >= 'wanted_pos' */
	546	static int locate_frame_in_index(AVIIndexEntry *entries,
	547	int nb_entries, int wanted_pos)
	548	{
	549	int a, b, m, pos;
	550
	551	a = 0;
	552	b = nb_entries - 1;
	553	while (a <= b) {
	554	m = (a + b) >> 1;
	555	pos = entries[m].pos;
	556	if (pos == wanted_pos)
	557	goto found;
	558	else if (pos > wanted_pos) {
	559	b = m - 1;
	560	} else {
	561	a = m + 1;
	562	}
	563	}
	564	m = a;
	565	if (m > 0)
	566	m--;
	567	found:
	568	return m;
	569	}
	570
	571	static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp)
	572	{
	573	AVIContext *avi = s->priv_data;
	574	AVStream *st;
	575	AVIStream *ast;
	576	int frame_number, i;
	577	int64_t pos;
	578
	579	if (!avi->index_loaded) {
	580	/* we only load the index on demand */
	581	avi_load_index(s);
	582	avi->index_loaded = 1;
	583	}
	584	if (stream_index < 0) {
	585	for(i = 0; i < s->nb_streams; i++) {
	586	st = s->streams[i];
	587	if (st->codec.codec_type == CODEC_TYPE_VIDEO)
	588	goto found;
	589	}
	590	return -1;
	591	found:
	592	stream_index = i;
	593	}
	594
	595	st = s->streams[stream_index];
	596	if (st->codec.codec_type != CODEC_TYPE_VIDEO)
	597	return -1;
	598	ast = st->priv_data;
	599	/* compute the frame number */
4fc2c644	600	frame_number = timestamp;
155e9ee9 FB	601	#ifdef DEBUG_SEEK
	602	printf("timestamp=%0.3f nb_indexes=%d frame_number=%d\n",
	603	(double)timestamp / AV_TIME_BASE,
	604	ast->nb_index_entries, frame_number);
	605	#endif
	606	/* find a closest key frame before */
	607	if (frame_number >= ast->nb_index_entries)
	608	return -1;
	609	while (frame_number >= 0 &&
	610	!(ast->index_entries[frame_number].flags & AVIIF_INDEX))
	611	frame_number--;
	612	if (frame_number < 0)
	613	return -1;
	614	ast->new_frame_offset = frame_number;
	615
	616	/* find the position */
	617	pos = ast->index_entries[frame_number].pos;
	618
	619	#ifdef DEBUG_SEEK
	620	printf("key_frame_number=%d pos=0x%llx\n",
	621	frame_number, pos);
	622	#endif
	623
	624	/* update the frame counters for all the other stream by looking
	625	at the positions just after the one found */
	626	for(i = 0; i < s->nb_streams; i++) {
	627	int j;
	628	if (i != stream_index) {
	629	st = s->streams[i];
	630	ast = st->priv_data;
	631	if (ast->nb_index_entries <= 0)
	632	return -1;
	633	j = locate_frame_in_index(ast->index_entries,
	634	ast->nb_index_entries,
	635	pos);
	636	/* get next frame */
	637	if ((j + 1) < ast->nb_index_entries)
	638	j++;
	639	/* extract the current frame number */
1fa3d65d	640	if (ast->sample_size==0)
155e9ee9 FB	641	ast->new_frame_offset = j;
	642	else
	643	ast->new_frame_offset = ast->index_entries[j].cum_len;
	644	}
	645	}
	646
	647	/* everything is OK now. We can update the frame offsets */
	648	for(i = 0; i < s->nb_streams; i++) {
	649	st = s->streams[i];
	650	ast = st->priv_data;
	651	ast->frame_offset = ast->new_frame_offset;
	652	#ifdef DEBUG_SEEK
	653	printf("%d: frame_offset=%d\n", i,
	654	ast->frame_offset);
	655	#endif
	656	}
	657	/* do the seek */
	658	pos += avi->movi_list;
	659	url_fseek(&s->pb, pos, SEEK_SET);
	660	return 0;
	661	}
	662
1101abfe	663	static int avi_read_close(AVFormatContext *s)
de6d9b64	664	{
5ae2c73e MN	665	int i;
5ae2c73e MN	666	AVIContext *avi = s->priv_data;
5ae2c73e MN	667
	668	for(i=0;i<s->nb_streams;i++) {
	669	AVStream *st = s->streams[i];
155e9ee9	670	AVIStream *ast = st->priv_data;
3144b152 MN	671	if(ast){
	672	av_free(ast->index_entries);
	673	av_free(ast);
	674	}
5ae2c73e	675	av_free(st->codec.extradata);
5e29abf8	676	av_free(st->codec.palctrl);
5ae2c73e MN	677	}
5ae2c73e MN	678
7458ccbb RS	679	if (avi->dv_demux)
	680	av_free(avi->dv_demux);
	681
c9a65ca8 FB	682	return 0;
	683	}
	684
	685	static int avi_probe(AVProbeData *p)
	686	{
	687	/* check file header */
	688	if (p->buf_size <= 32)
	689	return 0;
	690	if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
	691	p->buf[2] == 'F' && p->buf[3] == 'F' &&
	692	p->buf[8] == 'A' && p->buf[9] == 'V' &&
	693	p->buf[10] == 'I' && p->buf[11] == ' ')
	694	return AVPROBE_SCORE_MAX;
	695	else
	696	return 0;
	697	}
	698
	699	static AVInputFormat avi_iformat = {
	700	"avi",
	701	"avi format",
	702	sizeof(AVIContext),
	703	avi_probe,
	704	avi_read_header,
	705	avi_read_packet,
	706	avi_read_close,
155e9ee9	707	avi_read_seek,
c9a65ca8 FB	708	};
	709
	710	int avidec_init(void)
	711	{
	712	av_register_input_format(&avi_iformat);
de6d9b64 FB	713	return 0;
de6d9b64 FB	714	}