Martin Storsjö <mar...@martin.st> 于2023年8月25日周五 17:38写道: > > On Fri, 25 Aug 2023, Steven Liu wrote: > > >> > + list_len = (fourcc_str_len + 1) / 5; > >> > + // write the fourCcList field name > >> > + ff_amf_write_field_name(&p, "fourCcList"); > >> > + > >> > + // write the fourcc array length > >> > + ff_amf_write_array_start(&p, list_len); > >> > + > >> > + while(fourcc_data - rt->enhanced_codecs < fourcc_str_len) { > >> > + unsigned char fourcc[5]; > >> > + switch (AV_RN32(fourcc_data)) { > >> > + case MKTAG('h', 'v', 'c', '1'): > >> > >> This feels a bit convoluted to use AV_RN32 + MKTAG on data that is already > >> just a string - just using strncmp(fourcc_data, "hvc1", 4) would work just > > I want use strncmp at first, but i think strncmp will slower than > > switch uint32_t value, so i chose use uint32_t. or should i use > > strncmp? > > Yes, strncmp will be slower than switching on an uint32_t - but this isn't > really performance sensitive code. We do this once only, on startup, on a > handful of fourccs. So I believe code clarity is more important than > absolute performance here. Okay, i use strncasecmp next version patch. But i must told you, I think MKTAG is clarity than use if+strncmp to me, Because there looks like a fourcc codec list align code block. > > // Martin > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
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