使用GStreamer读取FFmpeg推送的RTSP循环流时遇错误求助

推流端（FFmpeg）命令 #

使用以下命令将静态MP4无限循环推为RTSP流：

ffmpeg  -flush_packets 1 -re -stream_loop -1 -i sample.mp4 -f rtsp rtsp://ip:8554/mystream

拉流端（GStreamer）尝试的命令及错误 #

第一次尝试的命令 #

命令1：

gst-launch-1.0 rtspsrc location=rtsp://ip:8554/mystream

命令2：

gst-launch-1.0 rtspsrc location=rtsp://ip:8554/mystream ! avdec_h264 ! autovideoconvert ! queue ! rtph264depay ! h264parse ! autovideosink

错误日志：

Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Progress: (open) Opening Stream
Progress: (connect) Connecting to rtsp://10.0.0.19:8554/mystream
Progress: (open) Retrieving server options
Progress: (open) Retrieving media info
Progress: (request) SETUP stream 0
Progress: (request) SETUP stream 1
Progress: (open) Opened Stream
Setting pipeline to PLAYING ...
New clock: GstSystemClock
Progress: (request) Sending PLAY request
Progress: (request) Sending PLAY request
Progress: (request) Sent PLAY request
WARNING: from element /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0: Delayed linking failed.
Additional debug info:
./grammar.y(510): gst_parse_no_more_pads (): /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0:
failed delayed linking some pad of GstRTSPSrc named rtspsrc0 to some pad of avdec_h264 named avdec_h264-0
ERROR: from element /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0: Internal data stream error.
Additional debug info:
gstrtspsrc.c(5653): gst_rtspsrc_loop (): /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0:
streaming stopped, reason not-linked (-1)
Execution ended after 0:00:01.552277296
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
Freeing pipeline ...

第二次尝试的命令 #

gst-launch-1.0 rtspsrc location=rtsp://ip:8554/mystream ! application/x-rtp,media=video,encoding-name=H264,clock-rate=90000 ! rtph264depay ! h264parse ! avdec_h264 ! videorate ! videoconvert ! queue! autovideosink

更新后的错误日志：

Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Progress: (open) Opening Stream
Progress: (connect) Connecting to rtsp://10.0.0.19:8554/mystream
Progress: (open) Retrieving server options
Progress: (open) Retrieving media info
Progress: (request) SETUP stream 0
Progress: (request) SETUP stream 1
Progress: (open) Opened Stream
Setting pipeline to PLAYING ...
New clock: GstSystemClock
Progress: (request) Sending PLAY request
Progress: (request) Sending PLAY request
Progress: (request) Sent PLAY request
0:00:02.180429398  3554 0x7f1cdc04e230 WARN                 basesrc gstbasesrc.c:3055:gst_base_src_loop:<udpsrc0> error: Internal data stream error.
0:00:02.180465192  3554 0x7f1cdc04e230 WARN                 basesrc gstbasesrc.c:3055:gst_base_src_loop:<udpsrc0> error: streaming stopped, reason not-linked (-1)
0:00:03.316770515  3554 0x7f1cdc032b20 WARN                 default grammar.y:510:gst_parse_no_more_pads:<rtspsrc0> warning: Delayed linking failed.
0:00:03.316823812  3554 0x7f1cdc032b20 WARN                 default grammar.y:510:gst_parse_no_more_pads:<rtspsrc0> warning: failed delayed linking some pad of GstRTSPSrc named rtspsrc0 to some pad of GstRtpH264Depay named rtph264depay0
WARNING: from element /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0: Delayed linking failed.
Additional debug info:
./grammar.y(510): gst_parse_no_more_pads (): /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0:
failed delayed linking some pad of GstRTSPSrc named rtspsrc0 to some pad of GstRtpH264Depay named rtph264depay0
0:00:04.018867523  3554 0x7f1cdc04e280 WARN                 basesrc gstbasesrc.c:3055:gst_base_src_loop:<udpsrc3> error: Internal data stream error.
0:00:04.018937057  3554 0x7f1cdc04e280 WARN                 basesrc gstbasesrc.c:3055:gst_base_src_loop:<udpsrc3> error: streaming stopped, reason not-linked (-1)
ERROR: from element /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0/GstUDPSrc:udpsrc3: Internal data stream error.
Additional debug info:
gstbasesrc.c(3055): gst_base_src_loop (): /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0/GstUDPSrc:udpsrc3:
streaming stopped, reason not-linked (-1)
Execution ended after 0:00:01.908870388
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to N

解决方案 #

问题根源 #

错误提示not-linked的核心原因：

1. RTSP流同时包含视频和音频两路流，但原有命令仅处理视频流，音频流无对应处理分支，导致链路断裂
2. 第一次尝试的命令中元素顺序错误（解码元件avdec_h264需放在解封装rtph264depay和解析h264parse之后）

修正后的GStreamer命令 #

方式1：仅处理视频流，忽略音频流

通过命名rtspsrc并指定视频流分支，确保链路完整：

gst-launch-1.0 rtspsrc location=rtsp://ip:8554/mystream latency=0 name=src src. ! queue ! application/x-rtp,media=video,encoding-name=H264 ! rtph264depay ! h264parse ! avdec_h264 ! autovideoconvert ! autovideosink

方式2：同时处理视频和音频流

添加音频处理分支，两路流并行处理：

gst-launch-1.0 rtspsrc location=rtsp://ip:8554/mystream latency=0 name=src \
src. ! queue ! application/x-rtp,media=video,encoding-name=H264 ! rtph264depay ! h264parse ! avdec_h264 ! autovideoconvert ! autovideosink \
src. ! queue ! application/x-rtp,media=audio,encoding-name=MPA ! rtppcmadepay ! mpegaudioparse ! avdec_mp3 ! audioconvert ! autoaudiosink

FFmpeg推流命令优化（可选） #

指定编码参数提升兼容性和稳定性：

ffmpeg -flush_packets 1 -re -stream_loop -1 -i sample.mp4 -c:v libx264 -preset ultrafast -tune zerolatency -c:a aac -f rtsp rtsp://ip:8554/mystream

内容的提问来源于stack exchange，提问作者khÜs h