avformat_new_stream() memory leak

[Jose Santiago]

avformat_new_stream() calls avcodec_alloc_context3() which can allocate data that is not free'd by the manual freeing of the codec context done by ff_free_stream() which is called by avformat_free_context(). In particular the st->codec->priv_data is allocated, but not free'd. The attached patch modifies ff_free_stream() to call avcodec_close() to properly close the codec context allocated in avformat_new_stream() .

For instance in the following code:

AVFormatContext * formatCtx;
AVCodec * codec;
AVStream * avStream;
AVOutputFormat * outputFormat;
const char * shortName = "mpegts";
const char * outputURL = "file://somefile.ts";

outputFormat = av_guess_format(shortName, outputURL, NULL);
assert(outputFormat != NULL);
avformat_alloc_output_context2(&formatCtx, outputFormat, shortName, outputURL);
assert(formatCtx != NULL);
avio_open2(&formatCtx->pb, outputURL, AVIO_FLAG_WRITE, NULL, NULL);
codec = avcodec_find_decoder(AV_CODEC_ID_H264);
assert(codec != NULL);
avStream = avformat_new_stream(formatCtx, codec);
assert(avStream != NULL);
avformat_write_header(formatCtx, NULL);
av_write_trailer(formatCtx);
avio_close(formatCtx->pb);
formatCtx->pb = NULL;
# Not all of the st[]->codec is free'd here.
avformat_free_context(formatCtx);

[Jose Santiago]

Patch to fix the muxer memory leak.

[Carl Eugen Hoyos]

Please send patches to the ffmpeg-devel mailing list where they will be reviewed.
(If you believe that this is not clearly explained on the New Ticket page, please tell us!)

[Jose Santiago]

OK. I sent the patch and the description to the ffmpeg-devel list.

[Carl Eugen Hoyos]

​http://thread.gmane.org/gmane.comp.video.ffmpeg.devel/167998

[Jose Santiago]

This issue is resolved and can be closed as fixed.

[Tom Seddon]

I think this is still a problem... maybe? I'm not very familiar with FFmpeg.

I posted a SO question about it. It's probably best viewed on SO, because there's external links in it and stuff - ​http://stackoverflow.com/questions/43389411/ - and overall it doesn't add much except for detail to the original report.

Is this a bug, or not?

If it's not a bug, how does one use the API in such a way that the problem doesn't arise?

Thanks,

--Tom

[Carl Eugen Hoyos]

Please consider posting your question on the libav-user mailing list.
In general, reopening months-old tickets is rarely useful.