# Error streaming mp3 files with HLS **URL:** \ **Category:** Wowza Streaming Engine\ **Tags:** vod\ **Created:** [June 12, 2020, 11:49am UTC](https://community.wowza.com/t/error-streaming-mp3-files-with-hls/55380 "2020-06-12T11:49:10Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Laura\_delli\_Paoli](https://avatars.discourse-cdn.com/v4/letter/l/e19adc/32.png) [@Laura\_delli\_Paoli](https://community.wowza.com/u/Laura_delli_Paoli)\ **Post date:** [June 12, 2020, 11:49am UTC](https://community.wowza.com/t/error-streaming-mp3-files-with-hls/55380/1 "2020-06-12T11:49:10Z")
Hi, I’m experiencing the following error trying to stream a big MP3 file (2.6 GB) from a VOD application using HLS (wowza version is 4.1.2) ERROR server comment 2020-06-11 17:21:00 - - - - - 59.9 - - - - - - - - open : java.lang.Exception: MP3 file format not valid. Zero duration. Seek will not function properly: 5421.mp3|at com.wowza.wms.mediareader.mp3.MediaReaderMP3.readMetadata(MediaReaderMP3.java:419)|at com.wowza.wms.mediareader.mp3.MediaReaderMP3.open(MediaReaderMP3.java:160)|at com.wowza.wms.httpstreamer.cupertinostreaming.file.HTTPStreamerCupertinoIndexFile.open(HTTPStreamerCupertinoIndexFile.java:292)|at com.wowza.wms.httpstreamer.cupertinostreaming.httpstreamer.HTTPStreamerSessionCupertino.getIndex(HTTPStreamerSessionCupertino.java:119)|at com.wowza.wms.httpstreamer.cupertinostreaming.httpstreamer.HTTPStreamerAdapterCupertinoStreamer.onPlaylist(HTTPStreamerAdapterCupertinoStreamer.java:2068)| This is the ouptut of ffprobe on the file: \ \ \ I tried to packetize the stream (as explained here [https://www.wowza.com/docs/how-to-improve-playback-of-lower-latency-apple-hls-streams](https://www.wowza.com/docs/how-to-improve-playback-of-lower-latency-apple-hls-streams)) without success. Is there any configuration needed on the server application? Can anyone help me? ---
**Author:** ![Rose\_Power-Wowza\_Com](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/rose_power-wowza_com/32/431_2.png) [@Rose\_Power-Wowza\_Com](https://community.wowza.com/u/Rose_Power-Wowza_Com)\ **Post date:** [June 12, 2020, 11:58am UTC](https://community.wowza.com/t/error-streaming-mp3-files-with-hls/55380/2 "2020-06-12T11:58:19Z")
It sounds like this is audio only correct? In which case, have you seen this article where it says that our audio only template transcodes the mp3 to AAC for player compatibility? Perhaps that could be the issue… [https://www.wowza.com/docs/how-to-transcode-only-the-audio-channel-of-an-incoming-stream](https://www.wowza.com/docs/how-to-transcode-only-the-audio-channel-of-an-incoming-stream) ---
**Author:** ![Rose\_Power-Wowza\_Com](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/rose_power-wowza_com/32/431_2.png) [@Rose\_Power-Wowza\_Com](https://community.wowza.com/u/Rose_Power-Wowza_Com)\ **Post date:** [June 12, 2020, 9:27pm UTC](https://community.wowza.com/t/error-streaming-mp3-files-with-hls/55380/3 "2020-06-12T21:27:28Z")
Oh sorry about that. Well it is critical that the keyframes be aligned if you’re doing any adaptive bitrate streaming. Are you? I can share some encoding examples for VOD with FFmpeg to see if it helps you out Streaming VOD requires: - A constant frame rate, to help ensure that all frames are aligned properly. - A constant keyframe interval, also known as a group of pictures (GOP). This is important so that segments are equally sized for Apple HLS, MPEG-DASH, Adobe HDS, and Microsoft Smooth Streaming. It also enables bitrate switching when delivering adaptive bitrate streams. - A bitrate-based encode, to ensure that all segments are close the same size, which helps to prevent buffering. **TROUBLESHOOTING:** If you have a VOD asset that Wowza Streaming Engine has trouble streaming, use the following FFprobe commands to troubleshoot. ( see bottom of the article ) [https://www.wowza.com/docs/how-to-encode-vod-using-ffmpeg-with-wowza-streaming-engine](https://www.wowza.com/docs/how-to-encode-vod-using-ffmpeg-with-wowza-streaming-engine) ---
**Author:** ![Laura\_delli\_Paoli](https://avatars.discourse-cdn.com/v4/letter/l/e19adc/32.png) [@Laura\_delli\_Paoli](https://community.wowza.com/u/Laura_delli_Paoli)\ **Post date:** [June 12, 2020, 1:46pm UTC](https://community.wowza.com/t/error-streaming-mp3-files-with-hls/55380/4 "2020-06-12T13:46:53Z")
Hi, thanks for your answer.Yes I’m trying to stream an audio file but It looks like the article refers to live streams, I’m using vod. Is there any limit in the size or bitrate of streamed files? ---
**Author:** ![Rose\_Power-Wowza\_Com](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/rose_power-wowza_com/32/431_2.png) [@Rose\_Power-Wowza\_Com](https://community.wowza.com/u/Rose_Power-Wowza_Com)\ **Post date:** [June 12, 2020, 9:44pm UTC](https://community.wowza.com/t/error-streaming-mp3-files-with-hls/55380/5 "2020-06-12T21:44:07Z")
**Audio bitrate** - The audio bitrate is the amount of data in 1 second of audio, also measured in Kbps. Audio bitrate can scale for bandwidth and device, too. Typical audio bitrates are 32 Kbps or 64 Kbps for voice content, and 96 Kbps, 128 Kbps, or 192 Kbps for music or more complex audio. ---
**Author:** ![Rose\_Power-Wowza\_Com](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/rose_power-wowza_com/32/431_2.png) [@Rose\_Power-Wowza\_Com](https://community.wowza.com/u/Rose_Power-Wowza_Com)\ **Post date:** [June 12, 2020, 9:34pm UTC](https://community.wowza.com/t/error-streaming-mp3-files-with-hls/55380/6 "2020-06-12T21:34:12Z")
Also…take a peek at this @Laura delli Paoli: \*\* Transcoder Decode/Audio/Parameters long parameter default.scaleChannels (0:do nothing, 2:force to stereo) which enables the AAC and MPEG-1 Layer 1-3 decoders to force a mono stream to stereo as part of decoding process (addresses the issue where source streams may switch between mono and stereo mid-stream) [https://www.wowza.com/docs/how-to-force-aac-and-mp3-audio-decode-to-be-stereo-when-using-transcoder](https://www.wowza.com/docs/how-to-force-aac-and-mp3-audio-decode-to-be-stereo-when-using-transcoder) If you STILL have issues, then let’s get it working for you in a support ticket. We are happy to help find the issue quickly. [https://www.wowza.com/support/open-ticket](https://www.wowza.com/support/open-ticket) ---
**Author:** ![Laura\_delli\_Paoli](https://avatars.discourse-cdn.com/v4/letter/l/e19adc/32.png) [@Laura\_delli\_Paoli](https://community.wowza.com/u/Laura_delli_Paoli)\ **Post date:** [June 13, 2020, 6:33pm UTC](https://community.wowza.com/t/error-streaming-mp3-files-with-hls/55380/7 "2020-06-13T18:33:34Z")
My file is 256Kbps. With the same wowza application I successfully stream file with a 96kbps bitrate without transcding. ---
**Author:** ![Rose\_Power-Wowza\_Com](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/rose_power-wowza_com/32/431_2.png) [@Rose\_Power-Wowza\_Com](https://community.wowza.com/u/Rose_Power-Wowza_Com)\ **Post date:** [June 13, 2020, 6:42pm UTC](https://community.wowza.com/t/error-streaming-mp3-files-with-hls/55380/8 "2020-06-13T18:42:15Z")
Thanks for that info. It all depends on your CPU capacity and your bandwidth available. If you need any more help, feel free to send a support ticket and we can guide you after looking more closely at your files. ---
**Author:** ![Laura\_delli\_Paoli](https://avatars.discourse-cdn.com/v4/letter/l/e19adc/32.png) [@Laura\_delli\_Paoli](https://community.wowza.com/u/Laura_delli_Paoli)\ **Post date:** [June 15, 2020, 10:54am UTC](https://community.wowza.com/t/error-streaming-mp3-files-with-hls/55380/9 "2020-06-15T10:54:36Z")
Hi, I upgraded the VM where Wowza run to 8 GB ram and 4 CPUs and I’m still unable to play a 2.7 GB file. Moreover I tried with a smalle file (just less that 2GB) and It plays succesfully (also with 2GB RAM).