From ac7f67b3f23a63e463fb881d960bc8f31a230292 Mon Sep 17 00:00:00 2001 From: wm4 Date: Thu, 14 Nov 2019 12:59:14 +0100 Subject: demux_mkv, stream: attempt to improve behavior in unseekable streams stream_skip() semantics were kind of bad, especially after the recent change to the stream code. Forward stream_skip() calls could still trigger a seek and fail, even if it was supposed to actually skip data. (Maybe the idea that stream_skip() should try to seek is worthless in the first place.) Rename it to stream_seek_skip() (takes absolute position now because I think that's better), and make it always skip if the stream is marked as forward. While we're at it, make EOF detection more robust. I guess s->eof shouldn't exist at all, since it's valid only "sometimes". It should be removed... but not today. A 1-byte stream_read_peek() call is good to get the s->eof flag set to a correct value. --- stream/stream.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'stream/stream.c') diff --git a/stream/stream.c b/stream/stream.c index 7fd6700cdd..271e268a1c 100644 --- a/stream/stream.c +++ b/stream/stream.c @@ -692,13 +692,13 @@ bool stream_seek(stream_t *s, int64_t pos) return stream_seek_unbuffered(s, pos); } -bool stream_skip(stream_t *s, int64_t len) +// Like stream_seek(), but strictly prefer skipping data instead of failing, if +// it's a forward-seek. +bool stream_seek_skip(stream_t *s, int64_t pos) { - if (!stream_seek(s, stream_tell(s) + len)) - return false; - // Make sure s->eof is set correctly, even if a seek happened. - stream_read_more(s, 1); - return true; + return !s->seekable && pos > stream_tell(s) + ? stream_skip_read(s, pos - stream_tell(s)) + : stream_seek(s, pos); } int stream_control(stream_t *s, int cmd, void *arg) @@ -732,7 +732,7 @@ int stream_skip_bom(struct stream *s) bstr data = {buf, len}; for (int n = 0; n < 3; n++) { if (bstr_startswith0(data, bom[n])) { - stream_skip(s, strlen(bom[n])); + stream_seek_skip(s, stream_tell(s) + strlen(bom[n])); return n; } } -- cgit v1.2.3