做app和做网站的区别,成都网站设计定制,网站建设成为,济宁企业网站建设公司在FFmpeg库中#xff0c;很多函数没有直接的参数可以设置超时。
那么有哪些函数可以通过设置 AVFormatContext 的 interrupt_callback 来实现超时控制#xff1f; avformat_open_input#xff1a; 打开输入文件或流。这个函数会阻塞#xff0c;尤其是在网络流的情况下很多函数没有直接的参数可以设置超时。
那么有哪些函数可以通过设置 AVFormatContext 的 interrupt_callback 来实现超时控制 avformat_open_input 打开输入文件或流。这个函数会阻塞尤其是在网络流的情况下可能会因为等待服务器响应而长时间阻塞。 avformat_find_stream_info 读取流信息。这个函数会尝试读取更多的数据来获得流的详细信息如果数据源响应缓慢也会阻塞。 av_read_frame 读取数据包。这个函数会读取下一帧的数据包如果数据源响应缓慢或者网络连接不稳定也会阻塞。 avio_read 从输入缓冲区读取数据这个函数也会阻塞。 avio_open 打开文件或网络资源以进行读取或写入的函数。 av_seek_frame 或 avformat_seek_file用于在媒体流中进行跳转操作 等等
总之在打开、关闭、读写网络流的时候都有可能遇到阻塞的问题。
以avformat_find_stream_info函数为例函数的调用关系如下:
avformat_find_stream_inforead_frame_internalff_read_packets-iformat-read_packetread_packet(rpsp.c)ff_sdp_demuxer.read_packet ff_rtsp_fetch_packetff_rtsp_fetch_packetread_packetff_rtsp_tcp_read_packetff_rtsp_read_replyffurl_read_completeretry_transfer_wrapperff_check_interrupt
ff_check_interrupt函数用于检测中断回调函数是否应该触发中断操作。
调用ff_check_interrupt函数的函数包括
async_check_interrupt in async.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
retry_transfer_wrapper in avio.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
get_current_fragment in dashdec.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
read_data in dashdec.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
reopen_demux_for_component in dashdec.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
dash_read_packet in dashdec.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
failing_write_packet in fifo_test.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
read_data in hls.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
read_data in hls.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
read_data in hls.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
hls_read in hlsproto.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
hls_read in hlsproto.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
libsrt_network_wait_fd_timeout in libsrt.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
libsrt_listen_connect in libsrt.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
ff_network_wait_fd_timeout in network.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
ff_network_sleep_interruptible in network.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
ff_poll_interrupt in network.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
ff_listen_connect in network.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
start_connect_attempt in network.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
rtp_read in rtpproto.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
udp_read_packet in rtsp.c (ffmpeg\ffmpeg-4.1.4\libavformat) :
以上函数被进一步调用的关系如下
retry_transfer_wrapperffurl_readwrapped_url_readio_read_packetcache_readconcat_readcrypto_readftp_getcftp_readftp_read_dirgopher_readhls_readhttp_getchttp_buf_readhttp_shutdownrtmpe_readrtmp_http_send_cmdrtmp_http_readrtmp_http_openff_rtmp_packet_readff_rtmp_packet_read_internalrtmp_writeudp_read_packetrtp_read_headersap_read_headersap_fetch_packetsrtp_readsubfile_readgnutls_url_pulltls_read_callbackmbedtls_recvurl_bio_breadtls_client_handshake_looptls_readtls_read_cbffurl_read_completeget_chunk_headerread_data_packetget_http_header_dataget_tcp_server_responsertmp_packet_read_one_chunkrtmp_calc_swfhashrtmp_handshakertmp_receive_hs_packetrtmp_server_handshakeff_rtsp_skip_packetff_rtsp_read_replyread_linertsp_read_announceff_rtsp_tcp_read_packetffurl_writeio_write_packetcrypto_writecrypto_closeftp_send_commandftp_writegopher_writehttp_write_replyhttp_connecthttp_writeff_rtmp_packet_writeff_rtp_check_and_send_back_rrff_rtp_send_punch_packetsff_rtp_send_rtcp_feedbackff_rtsp_read_replyff_rtsp_tcp_write_packetgnutls_url_pushhttp_proxy_openhttp_proxy_writehttp_shutdownicecast_writeism_writembedtls_sendmd5_closeprompeg_write_fecrtmp_handshakertmp_send_hs_packetrtmp_server_handshakertmpe_writertp_writertsp_send_cmd_with_content_asyncrtsp_send_replysap_write_closesap_write_packetsend_command_packetsrtp_writetee_writetls_client_handshaketls_client_handshake_looptls_shutdown_clienttls_writetls_write_callbacktls_write_cburl_bio_bwriteasync_check_interruptasync_buffer_taskasync_openasync_read_internalasync_seekff_listen_connectsctp_openunix_openff_network_sleep_interruptiblehttp_read_streamff_network_wait_fd_timeouttcp_readtcp_writeff_poll_interruptff_listen_connectff_connect_parallelget_current_fragmentread_datalibsrt_listen_connectlibsrt_setuplibsrt_network_wait_fd_timeoutlibsrt_listenlibsrt_listen_connectlibsrt_readlibsrt_writeread_datahls_read_headerpulse_read_packetreopen_demux_for_componenttls_client_handshake_loopreopen_demux_for_componentopen_demux_for_componentrecheck_discard_flagsdash_read_packetdash_seekstart_connect_attemptff_connect_paralleludp_read_packetread_packetdash_read_packetAVInputFormat ff_dash_demuxer {.name dash,.long_name NULL_IF_CONFIG_SMALL(Dynamic Adaptive Streaming over HTTP),.priv_class dash_class,.priv_data_size sizeof(DASHContext),.read_probe dash_probe,.read_header dash_read_header,.read_packet dash_read_packet,.read_close dash_close,.read_seek dash_read_seek,.flags AVFMT_NO_BYTE_SEEK,};failing_write_packetAVOutputFormat ff_fifo_test_muxer {.name fifo_test,.long_name NULL_IF_CONFIG_SMALL(Fifo test muxer),.priv_data_size sizeof(FailingMuxerContext),.write_header failing_write_header,.write_packet failing_write_packet,.write_trailer failing_write_trailer,.deinit failing_deinit,.priv_class failing_muxer_class,.flags AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,};hls_readconst URLProtocol ff_hls_protocol {.name hls,.url_open hls_open,.url_read hls_read,.url_close hls_close,.flags URL_PROTOCOL_FLAG_NESTED_SCHEME,.priv_data_size sizeof(HLSContext),};rtp_readconst URLProtocol ff_rtp_protocol {.name rtp,.url_open rtp_open,.url_read rtp_read,.url_write rtp_write,.url_close rtp_close,.url_get_file_handle rtp_get_file_handle,.url_get_multi_file_handle rtp_get_multi_file_handle,.priv_data_size sizeof(RTPContext),.flags URL_PROTOCOL_FLAG_NETWORK,.priv_data_class rtp_class,};
