av_free(swf);
static int swf_write_trailer(AVFormatContext *s){    SWFContext *swf = s->priv_data;    ByteIOContext *pb = &s->pb;    AVCodecContext *enc, *video_enc;    int file_size, i;    video_enc = NULL;    for(i=0;i<s->nb_streams;i++) {        enc = &s->streams[i]->codec;        if (enc->codec_type == CODEC_TYPE_VIDEO)            video_enc = enc;    }    put_swf_tag(s, TAG_END);    put_swf_end_tag(s);        put_flush_packet(&s->pb);    /* patch file size and number of frames if not streamed */    if (!url_is_streamed(&s->pb) && video_enc) {        file_size = url_ftell(pb);        url_fseek(pb, 4, SEEK_SET);        put_le32(pb, file_size);        url_fseek(pb, swf->duration_pos, SEEK_SET);        put_le16(pb, video_enc->frame_number);    }    av_free(swf);    return 0;}