/* stream generic header */        strh = start_tag(pb, "strh");        switch(stream->codec_type) {        case CODEC_TYPE_VIDEO:            put_tag(pb, "vids");            put_le32(pb, stream->codec_tag);            put_le32(pb, 0); /* flags */            put_le16(pb, 0); /* priority */            put_le16(pb, 0); /* language */            put_le32(pb, 0); /* initial frame */                        put_le32(pb, stream->frame_rate_base); /* scale */            put_le32(pb, stream->frame_rate); /* rate */            put_le32(pb, 0); /* start */            avi->frames_hdr_strm[i] = url_ftell(pb); /* remember this offset to fill later */            put_le32(pb, nb_frames); /* length, XXX: fill later */            put_le32(pb, 1024 * 1024); /* suggested buffer size */            put_le32(pb, -1); /* quality */            put_le32(pb, stream->width * stream->height * 3); /* sample size */            put_le16(pb, 0);            put_le16(pb, 0);            put_le16(pb, stream->width);            put_le16(pb, stream->height);            break;        case CODEC_TYPE_AUDIO:            put_tag(pb, "auds");            put_le32(pb, 1); /* tag */            put_le32(pb, 0); /* flags */            put_le16(pb, 0); /* priority */            put_le16(pb, 0); /* language */            put_le32(pb, 0); /* initial frame */            parse_specific_params(stream, &au_byterate, &au_ssize, &au_scale);            put_le32(pb, au_scale); /* scale */            put_le32(pb, au_byterate); /* rate */            put_le32(pb, 0); /* start */            avi->frames_hdr_strm[i] = url_ftell(pb); /* remember this offset to fill later */            put_le32(pb, 0); /* length, XXX: filled later */            put_le32(pb, 12 * 1024); /* suggested buffer size */            put_le32(pb, -1); /* quality */            put_le32(pb, au_ssize); /* sample size */            put_le32(pb, 0);            put_le32(pb, 0);            break;        default:            av_abort();        }        end_tag(pb, strh);        strf = start_tag(pb, "strf");        switch(stream->codec_type) {        case CODEC_TYPE_VIDEO:	    put_bmp_header(pb, stream, codec_bmp_tags, 0);            break;        case CODEC_TYPE_AUDIO:            if (put_wav_header(pb, stream) < 0) {                av_free(avi);                return -1;            }            break;        default:            av_abort();        }        end_tag(pb, strf);		if (!url_is_streamed(pb)) {	    unsigned char tag[5];	    int j;                /* Starting to lay out AVI OpenDML master index. 	     * We want to make it JUNK entry for now, since we'd	     * like to get away without making AVI an OpenDML one 	     * for compatibility reasons.	     */	    avi->indexes[i].entry = avi->indexes[i].ents_allocated = 0;	    avi->indexes[i].indx_start = start_tag(pb, "JUNK"); 	    put_le16(pb, 4);        /* wLongsPerEntry */	    put_byte(pb, 0);        /* bIndexSubType (0 == frame index) */	    put_byte(pb, 0);        /* bIndexType (0 == AVI_INDEX_OF_INDEXES) */	    put_le32(pb, 0);        /* nEntriesInUse (will fill out later on) */	    put_tag(pb, avi_stream2fourcc(&tag[0], i, stream->codec_type));	                            /* dwChunkId */	    put_le64(pb, 0);        /* dwReserved[3]	    put_le32(pb, 0);           Must be 0.    */	    for (j=0; j < AVI_MASTER_INDEX_SIZE * 2; j++)	         put_le64(pb, 0);	    end_tag(pb, avi->indexes[i].indx_start);	}	        end_tag(pb, list2);    }        if (!url_is_streamed(pb)) {        /* AVI could become an OpenDML one, if it grows beyond 2Gb range */        avi->odml_list = start_tag(pb, "JUNK");        put_tag(pb, "odml");        put_tag(pb, "dmlh");        put_le32(pb, 248);        for (i = 0; i < 248; i+= 4)             put_le32(pb, 0);        end_tag(pb, avi->odml_list);    }    end_tag(pb, list1);        avi->movi_list = start_tag(pb, "LIST");    put_tag(pb, "movi");    put_flush_packet(pb);    return 0;}static int avi_write_ix(AVFormatContext *s){    ByteIOContext *pb = &s->pb;    AVIContext *avi = s->priv_data;    unsigned char tag[5];    unsigned char ix_tag[] = "ix00";    int i, j;        if (avi->riff_id > AVI_MASTER_INDEX_SIZE)        return -1;        for (i=0;i<s->nb_streams;i++) {	 offset_t ix, pos;	 	 avi_stream2fourcc(&tag[0], i, s->streams[i]->codec.codec_type);	 ix_tag[3] = '0' + i;	 	 /* Writing AVI OpenDML leaf index chunk */	 ix = url_ftell(pb); 	 put_tag(pb, &ix_tag[0]);     /* ix?? */	 put_le32(pb, avi->indexes[i].entry * 8 + 24); 	                              /* chunk size */         put_le16(pb, 2);             /* wLongsPerEntry */	 put_byte(pb, 0);             /* bIndexSubType (0 == frame index) */ 	 put_byte(pb, 1);             /* bIndexType (1 == AVI_INDEX_OF_CHUNKS) */	 put_le32(pb, avi->indexes[i].entry);          	                              /* nEntriesInUse */	 put_tag(pb, &tag[0]);        /* dwChunkId */	 put_le64(pb, avi->movi_list);/* qwBaseOffset */	 put_le32(pb, 0);             /* dwReserved_3 (must be 0) */         for (j=0; j<avi->indexes[i].entry; j++) {             AVIIentry* ie = avi_get_ientry(&avi->indexes[i], j);	     put_le32(pb, ie->pos + 8);	     put_le32(pb, ((uint32_t)ie->len & ~0x80000000) |	                  (ie->flags & 0x10 ? 0 : 0x80000000));         }	 put_flush_packet(pb);         pos = url_ftell(pb);		 /* Updating one entry in the AVI OpenDML master index */	 url_fseek(pb, avi->indexes[i].indx_start - 8, SEEK_SET);	 put_tag(pb, "indx");                 /* enabling this entry */	 url_fskip(pb, 8);	 put_le32(pb, avi->riff_id);          /* nEntriesInUse */	 url_fskip(pb, 16*avi->riff_id);	 put_le64(pb, ix);                    /* qwOffset */	 put_le32(pb, pos - ix);              /* dwSize */	 put_le32(pb, avi->indexes[i].entry); /* dwDuration */	 url_fseek(pb, pos, SEEK_SET);    }    return 0;}static int avi_write_idx1(AVFormatContext *s){    ByteIOContext *pb = &s->pb;    AVIContext *avi = s->priv_data;    offset_t file_size, idx_chunk;    int i, n, nb_frames, au_byterate, au_ssize, au_scale;    AVCodecContext *stream;    unsigned char tag[5];    if (!url_is_streamed(pb)) {	AVIIentry* ie = 0, *tie;	int entry[MAX_STREAMS];	int empty, stream_id = -1;	idx_chunk = start_tag(pb, "idx1");	memset(&entry[0], 0, sizeof(entry));	do {	    empty = 1;	    for (i=0; i<s->nb_streams; i++) {	         if (avi->indexes[i].entry <= entry[i])		     continue;		 		 tie = avi_get_ientry(&avi->indexes[i], entry[i]);		 if (empty || tie->pos < ie->pos) {		     ie = tie; 		     stream_id = i;		 }		 empty = 0;	    }	    if (!empty) {	        avi_stream2fourcc(&tag[0], stream_id, 		                  s->streams[stream_id]->codec.codec_type); 	        put_tag(pb, &tag[0]);		put_le32(pb, ie->flags);                put_le32(pb, ie->pos);                put_le32(pb, ie->len);		entry[stream_id]++;	    }	} while (!empty);	end_tag(pb, idx_chunk);        /* Fill in frame/sample counters */	file_size = url_ftell(pb);        nb_frames = 0;        for(n=0;n<s->nb_streams;n++) {            if (avi->frames_hdr_strm[n] != 0) {                stream = &s->streams[n]->codec;                url_fseek(pb, avi->frames_hdr_strm[n], SEEK_SET);                if (stream->codec_type == CODEC_TYPE_VIDEO) {                    put_le32(pb, stream->frame_number);                     if (nb_frames < stream->frame_number)                        nb_frames = stream->frame_number;                } else {                    if (stream->codec_id == CODEC_ID_MP2 || stream->codec_id == CODEC_ID_MP3) {                        put_le32(pb, stream->frame_number);                        nb_frames += stream->frame_number;                    } else {                        parse_specific_params(stream, &au_byterate, &au_ssize, &au_scale);                        put_le32(pb, avi->audio_strm_length[n] / au_ssize);                    }                }            }       }       if (avi->frames_hdr_all != 0) {           url_fseek(pb, avi->frames_hdr_all, SEEK_SET);           put_le32(pb, nb_frames);        }       url_fseek(pb, file_size, SEEK_SET);    }    return 0;}static int avi_write_packet(AVFormatContext *s, int stream_index,                            const uint8_t *buf, int size, int64_t pts){    AVIContext *avi = s->priv_data;    ByteIOContext *pb = &s->pb;    unsigned char tag[5];    unsigned int flags;    AVCodecContext *enc;    if (url_ftell(pb) - avi->riff_start > AVI_MAX_RIFF_SIZE) {         avi_write_ix(s);        end_tag(pb, avi->movi_list);        	if (avi->riff_id == 1)	    avi_write_idx1(s);	end_tag(pb, avi->riff_start);	avi->movi_list = avi_start_new_riff(avi, pb, "AVIX", "movi");    }        enc = &s->streams[stream_index]->codec;    avi_stream2fourcc(&tag[0], stream_index, enc->codec_type);    if (enc->codec_type == CODEC_TYPE_AUDIO) {       avi->audio_strm_length[stream_index] += size;       flags = 0x10;    } else       flags = enc->coded_frame->key_frame ? 0x10 : 0x00;    if (!url_is_streamed(&s->pb)) {        AVIIndex* idx = &avi->indexes[stream_index];	int cl = idx->entry / AVI_INDEX_CLUSTER_SIZE;	int id = idx->entry % AVI_INDEX_CLUSTER_SIZE;        if (idx->ents_allocated <= idx->entry) {	    idx->cluster = av_realloc(idx->cluster, (cl+1)*sizeof(void*)); 	    if (!idx->cluster)	        return -1;            idx->cluster[cl] = av_malloc(AVI_INDEX_CLUSTER_SIZE*sizeof(AVIIentry));	    if (!idx->cluster[cl])		return -1;	    idx->ents_allocated += AVI_INDEX_CLUSTER_SIZE;	} 		idx->cluster[cl][id].flags = flags;         idx->cluster[cl][id].pos = url_ftell(pb) - avi->movi_list;        idx->cluster[cl][id].len = size;	idx->entry++;    }        put_buffer(pb, tag, 4);    put_le32(pb, size);    put_buffer(pb, buf, size);    if (size & 1)        put_byte(pb, 0);    put_flush_packet(pb);    return 0;}static int avi_write_trailer(AVFormatContext *s){    AVIContext *avi = s->priv_data;    ByteIOContext *pb = &s->pb;    int res = 0;    int i, j, n, nb_frames;    offset_t file_size;    if (avi->riff_id == 1) {        end_tag(pb, avi->movi_list);        res = avi_write_idx1(s);	end_tag(pb, avi->riff_start);    } else {        avi_write_ix(s);        end_tag(pb, avi->movi_list);	end_tag(pb, avi->riff_start);        file_size = url_ftell(pb);	url_fseek(pb, avi->odml_list - 8, SEEK_SET);	put_tag(pb, "LIST"); /* Making this AVI OpenDML one */	url_fskip(pb, 16);        for (n=nb_frames=0;n<s->nb_streams;n++) {             AVCodecContext *stream = &s->streams[n]->codec;             if (stream->codec_type == CODEC_TYPE_VIDEO) {                 if (nb_frames < stream->frame_number)                     nb_frames = stream->frame_number;             } else {                 if (stream->codec_id == CODEC_ID_MP2 || stream->codec_id == CODEC_ID_MP3) {                     nb_frames += stream->frame_number;                }            }        }	put_le32(pb, nb_frames);	url_fseek(pb, file_size, SEEK_SET);    }    put_flush_packet(pb);    for (i=0; i<MAX_STREAMS; i++) {	 for (j=0; j<avi->indexes[i].ents_allocated/AVI_INDEX_CLUSTER_SIZE; j++)              av_free(avi->indexes[i].cluster[j]);	 av_free(avi->indexes[i].cluster);	 avi->indexes[i].cluster = NULL;	 avi->indexes[i].ents_allocated = avi->indexes[i].entry = 0;    }        return res;}static AVOutputFormat avi_oformat = {    "avi",    "avi format",    "video/x-msvideo",    "avi",    sizeof(AVIContext),    CODEC_ID_MP2,    CODEC_ID_MPEG4,    avi_write_header,    avi_write_packet,    avi_write_trailer,};int avienc_init(void){    av_register_output_format(&avi_oformat);    return 0;}#endif //CONFIG_ENCODERS