gstreamer多通道大于8通道

Question

下午好，到目前为止，我一直在使用gstreamer来流式传输8声道的音频，没有任何问题。我在audacity中生成了8个单声道，并导出了一个wav文件。

我最近被要求支持16个频道，我惊讶地发现16个频道(或8个以上的任何频道)不被支持。用于流式传输wav文件的命令行gstreamer命令如下所示：

GST_DEBUG=3 gst-launch-1.0 filesrc location=~/Desktop/8ch_16_test_diagwav.wav ! decodebin ! audioconvert ! audioresample ! audioconvert ! audio/x-raw,format=S16BE,rate=48000,channels=16 ! filesink location=/tmp/filesink0

当使用16通道文件运行时，我得到以下错误：

Setting pipeline to PAUSED ...
0:00:00.041995106  3534 0x55b0024a4e10 WARN                 basesrc gstbasesrc.c:3583:gst_base_src_start_complete:<filesrc0> pad not activated yet
Pipeline is PREROLLING ...
0:00:00.046842761  3534 0x7f833806ec00 FIXME                default gstutils.c:3981:gst_pad_create_stream_id_internal:<wavparse0:src> Creating random stream-id, consider implementing a deterministic way of creating a stream-id
0:00:00.091236225  3534 0x7f833806ec00 WARN         audio-resampler audio-resampler.c:274:convert_taps_gint16_c: can't find exact taps
0:00:00.091319797  3534 0x7f833806ec00 WARN            audioconvert gstaudioconvert.c:654:gst_audio_convert_fixate_channels:<audioconvert1> invalid or unexpected channel-positions
0:00:00.091329274  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:668:gst_audio_convert_fixate_channels:<audioconvert1> Have no default layout for 16 channels
0:00:00.091339971  3534 0x7f833806ec00 ERROR             audio-info audio-info.c:304:gst_audio_info_from_caps: no channel-mask property given
0:00:00.091344101  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:778:gst_audio_convert_set_caps:<audioconvert1> invalid output caps
0:00:00.091356433  3534 0x7f833806ec00 WARN           basetransform gstbasetransform.c:1362:gst_base_transform_setcaps:<audioconvert1> FAILED to configure incaps audio/x-raw, format=(string)S16LE, layout=(string)interleaved, channels=(int)8, channel-mask=(bitmask)0x0000000000000c3f, rate=(int)48000 and outcaps audio/x-raw, layout=(string)interleaved, rate=(int)48000, format=(string)S16BE, channels=(int)16
0:00:00.091398546  3534 0x7f833806ec00 WARN            audioconvert gstaudioconvert.c:654:gst_audio_convert_fixate_channels:<audioconvert1> invalid or unexpected channel-positions
0:00:00.091404430  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:668:gst_audio_convert_fixate_channels:<audioconvert1> Have no default layout for 16 channels
0:00:00.091411526  3534 0x7f833806ec00 ERROR             audio-info audio-info.c:304:gst_audio_info_from_caps: no channel-mask property given
0:00:00.091415084  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:778:gst_audio_convert_set_caps:<audioconvert1> invalid output caps
0:00:00.091423006  3534 0x7f833806ec00 WARN           basetransform gstbasetransform.c:1362:gst_base_transform_setcaps:<audioconvert1> FAILED to configure incaps audio/x-raw, format=(string)S16LE, layout=(string)interleaved, channels=(int)8, channel-mask=(bitmask)0x0000000000000c3f, rate=(int)48000 and outcaps audio/x-raw, layout=(string)interleaved, rate=(int)48000, format=(string)S16BE, channels=(int)16
0:00:00.091461862  3534 0x7f833806ec00 WARN            audioconvert gstaudioconvert.c:654:gst_audio_convert_fixate_channels:<audioconvert1> invalid or unexpected channel-positions
0:00:00.091467389  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:668:gst_audio_convert_fixate_channels:<audioconvert1> Have no default layout for 16 channels
0:00:00.091473940  3534 0x7f833806ec00 ERROR             audio-info audio-info.c:304:gst_audio_info_from_caps: no channel-mask property given
0:00:00.091477330  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:778:gst_audio_convert_set_caps:<audioconvert1> invalid output caps
0:00:00.091484711  3534 0x7f833806ec00 WARN           basetransform gstbasetransform.c:1362:gst_base_transform_setcaps:<audioconvert1> FAILED to configure incaps audio/x-raw, format=(string)S16LE, layout=(string)interleaved, channels=(int)8, channel-mask=(bitmask)0x0000000000000c3f, rate=(int)48000 and outcaps audio/x-raw, layout=(string)interleaved, rate=(int)48000, format=(string)S16BE, channels=(int)16
0:00:00.091521324  3534 0x7f833806ec00 WARN            audioconvert gstaudioconvert.c:654:gst_audio_convert_fixate_channels:<audioconvert1> invalid or unexpected channel-positions
0:00:00.091526722  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:668:gst_audio_convert_fixate_channels:<audioconvert1> Have no default layout for 16 channels
0:00:00.091533191  3534 0x7f833806ec00 ERROR             audio-info audio-info.c:304:gst_audio_info_from_caps: no channel-mask property given
0:00:00.091536562  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:778:gst_audio_convert_set_caps:<audioconvert1> invalid output caps
0:00:00.091543448  3534 0x7f833806ec00 WARN           basetransform gstbasetransform.c:1362:gst_base_transform_setcaps:<audioconvert1> FAILED to configure incaps audio/x-raw, format=(string)S16LE, layout=(string)interleaved, channels=(int)8, channel-mask=(bitmask)0x0000000000000c3f, rate=(int)48000 and outcaps audio/x-raw, layout=(string)interleaved, rate=(int)48000, format=(string)S16BE, channels=(int)16
0:00:00.091554349  3534 0x7f833806ec00 WARN                wavparse gstwavparse.c:2293:gst_wavparse_loop:<wavparse0> error: Internal data stream error.
0:00:00.091558663  3534 0x7f833806ec00 WARN                wavparse gstwavparse.c:2293:gst_wavparse_loop:<wavparse0> error: streaming stopped, reason not-negotiated (-4)
ERROR: from element /GstPipeline:pipeline0/GstDecodeBin:decodebin0/GstWavParse:wavparse0: Internal data stream error.
Additional debug info:
gstwavparse.c(2293): gst_wavparse_loop (): /GstPipeline:pipeline0/GstDecodeBin:decodebin0/GstWavParse:wavparse0:
streaming stopped, reason not-negotiated (-4)
0:00:00.091614021  3534 0x7f833806ec00 WARN            audioconvert gstaudioconvert.c:654:gst_audio_convert_fixate_channels:<audioconvert1> invalid or unexpected channel-positions
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
0:00:00.091619464  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:668:gst_audio_convert_fixate_channels:<audioconvert1> Have no default layout for 16 channels
0:00:00.091662384  3534 0x7f833806ec00 ERROR             audio-info audio-info.c:304:gst_audio_info_from_caps: no channel-mask property given
0:00:00.091681343  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:778:gst_audio_convert_set_caps:<audioconvert1> invalid output caps
0:00:00.091701845  3534 0x7f833806ec00 WARN           basetransform gstbasetransform.c:1362:gst_base_transform_setcaps:<audioconvert1> FAILED to configure incaps audio/x-raw, format=(string)S16LE, layout=(string)interleaved, channels=(int)8, channel-mask=(bitmask)0x0000000000000c3f, rate=(int)48000 and outcaps audio/x-raw, layout=(string)interleaved, rate=(int)48000, format=(string)S16BE, channels=(int)16
0:00:00.091767321  3534 0x7f833806ec00 WARN            audioconvert gstaudioconvert.c:654:gst_audio_convert_fixate_channels:<audioconvert1> invalid or unexpected channel-positions
0:00:00.091773142  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:668:gst_audio_convert_fixate_channels:<audioconvert1> Have no default layout for 16 channels
0:00:00.091779617  3534 0x7f833806ec00 ERROR             audio-info audio-info.c:304:gst_audio_info_from_caps: no channel-mask property given
0:00:00.091797568  3534 0x7f833806ec00 ERROR           audioconvert gstaudioconvert.c:778:gst_audio_convert_set_caps:<audioconvert1> invalid output caps
0:00:00.091805352  3534 0x7f833806ec00 WARN           basetransform gstbasetransform.c:1362:gst_base_transform_setcaps:<audioconvert1> FAILED to configure incaps audio/x-raw, format=(string)S16LE, layout=(string)interleaved, channels=(int)8, channel-mask=(bitmask)0x0000000000000c3f, rate=(int)48000 and outcaps audio/x-raw, layout=(string)interleaved, rate=(int)48000, format=(string)S16BE, channels=(int)16
Freeing pipeline ...

当将8channel文件和channel =8与从同一audacity项目生成的wav文件一起使用时，一切正常。

目前，使用

linux
gst-launch-1.0 version 1.14.4
GStreamer 1.14.4

是不是根本不可能在命令行中使用gstreamer流式传输一个16通道的wav文件？我试着查看各种标志，如交错，通道位置等，但没有足够的经验，不知道可能需要什么。

任何帮助或链接都将受到欢迎。

Answer 1

也许在Audacity方面出了什么问题？

下面的代码为我创建了一个16通道.wav文件：

gst-launch-1.0 audiotestsrc is-live=true ! \
  audio/x-raw,format=S16BE,rate=48000,channels=16 ! \
  audioresample ! audioconvert ! wavenc ! filesink location=x.wav

ffprobe：

Input #0, wav, from 'x.wav':
  Duration: 00:23:18.06, bitrate: 24 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, 16 channels, s16, 12288 kb/s

该文件也可以在gst-play-1.0 x.wav上正常播放。这些都在GStreamer 1.16.2上。

Answer 2

经过相当多的搜索和实验，我终于找到了一个可行的解决方案。

gst-launch-1.0 filesrc location=16ch_16bit_10s.wav ! decodebin ! capssetter caps="audio/x-raw,channels=16,rate=48000,channel-mask=(bitmask)0xffff" ! audioconvert ! audioresample ! "audio/x-raw,rate=48000,format=S16BE" ! queue ! capssetter caps="audio/x-raw,channels=16,rate=48000,channel-mask=(bitmask)0xffff" ! audioconvert ! audioresample ! filesink location=audiosink

其中位掩码值=(2^通道)-1，采用十六进制字符串格式。

这主要是通过跟踪和错误发现的，使用以下内容作为参考：interleaving 4 channels of audio into vorbisenc or opusenc in gstreamer

不幸的是，我没有足够的经验(或足够聪明)来完全理解为什么这样做是可行的。capsetter实际上是做什么的，为什么上游和下游之间需要一个"audio/x-raw,rate=48000,format=S16BE"，这是任何人都不知道的。如果有人能编辑/评论一个更好的解释可能会更好？

有了这个解决方案，我可以在16-24位和1,2,4,8,16通道之间切换。