[FFmpeg-devel] Patch to libavc/opus to create extradata if missing

[Lynne]

Jan 3, 2021, 23:48 by jon at jonb.org:

>
>
> On Sun, Jan 3, 2021, at 2:25 PM, Lynne wrote:
>
>> > +    /* Input sample rate (0 = unspecified) */> +    bytestream_put_le32  (&bs, 0);
>> Put in 48000 here. Stream copy will preserve extradata, and we don't want to
>> generate weird streams, even if our decoder ignores this.
>>
>> > +    /* Channel count */> +    bytestream_put_byte  (&bs, codecpar->channels);> +    /* Mapping family */> +    bytestream_put_byte  (&bs, 0x0);
>> This will only work for mono and stereo. The decoder will error out if more than
>> 2 channels are present. For now maybe error out if the number of channels is greater than 2?
>>
>
> Ok! Sample rate changed to 48000. If codecpar->channels is greater than 2, AVERROR_INVALIDDATA will be returned. Please advise if there is a better error code.
>
> Thanks Lynne!
>

> +static int opus_write_extradata(AVCodecParameters *codecpar) {
Function opening brackets must be put by themselves on a new line.

> +    if (codecpar->channels > 2) { 
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    ret = ff_alloc_extradata(codecpar, 19);
> +    if (ret < 0) {
> +        return ret;
> +    }
We don't wrap 1-line conditions in brackets, so just remove them.

> +                av_log(s1, AV_LOG_ERROR, 
> +                        "Error creating opus extradata: %s\n",
> +                        av_err2str(ret));
Weird indentation. There's an extra space in the 2 lines.

Apart from that LGTM.