[PATCH] -vo lavf

older
[PATCH] Remove a bunch of useless...

Nicolas George

28 Oct 2010 28 Oct '10

8:05 p.m.

Hi. This issue was raised last February: it would be nice to have an output driver similar to yuv4mpeg, but supporting timestamps and variable framerate, more pixel formats and possibly, in the future, muxing of the audio stream. Here is a try at implementing it. It uses lavf to mux uncompressed video frames into any supported container. Note that I needed to change vf_vo so that VOCTRL_DRAW_IMAGE would get the pts as an additional argument. Regards, -- Nicolas George

Attachments:

mplayer-volavf-20101028-2158-01-volavf.diff (text/x-diff — 11.5 KB)
signature.asc (application/pgp-signature — 198 bytes)

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Nicolas George

7 Nov 7 Nov

11:07 a.m.

Le septidi 7 brumaire, an CCXIX, Nicolas George a écrit :

...

This issue was raised last February: it would be nice to have an output driver similar to yuv4mpeg, but supporting timestamps and variable framerate, more pixel formats and possibly, in the future, muxing of the audio stream.

Here is a try at implementing it. It uses lavf to mux uncompressed video frames into any supported container.

Note that I needed to change vf_vo so that VOCTRL_DRAW_IMAGE would get the pts as an additional argument.

Ping? Any advice? Regards, -- Nicolas George

Reimar Döffinger

4:54 p.m.

On Thu, Oct 28, 2010 at 10:05:03PM +0200, Nicolas George wrote:

...

Note that I needed to change vf_vo so that VOCTRL_DRAW_IMAGE would get the pts as an additional argument.

I'd prefer you didn't, I'd prefer to save myself having to think if there might be any compatibilty issue with some calling conventions. Also, while it is a hack there is already a vo_pts variable. Lastly, I miss the most important information: why? What is the big advantage over using mencoder?

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+static AVRational parse_rational(const char *str) +{ + AVRational r; + double d; + char dummy; + + if (sscanf(str, "%d/%d%c", &r.num, &r.den, &dummy) == 2) + return r; + if (sscanf(str, "%lf%c", &d, &dummy) == 1) + return av_d2q(d, 30000); /* must accept 29.97003 */ + r.num = r.den = 0; + return r; +}

I'm sure there are already several functions that do that kind of parsing, I'd prefer not to have yet another one.

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+static int preinit(const char *arg) +{ + avcodec_register_all(); + av_register_all();

Wasn't this FFmpeg initialization code moved to some common code or something?

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+ if (!fps.num || !fps.den) { + mp_msg(MSGT_VO, MSGL_ERR, "vo-lavf: invalid fps\n"); + return -1;

What about < 0?

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+ if (!encoder) { + mp_msg(MSGT_VO, MSGL_ERR, "vo-lavf: encoder not found\n"); + free_avf(); + return -1; + } + if (avcodec_open(video_str->codec, encoder) < 0) { + mp_msg(MSGT_VO, MSGL_ERR, "vo-lavf: unable to open encoder\n"); + free_avf(); + return -1; + } + if (av_set_parameters(avf, NULL) < 0) { + mp_msg(MSGT_VO, MSGL_ERR, "vo-lavf: unable to set parameters\n"); + free_avf(); + return -1; + } + if (!(output_format->flags & AVFMT_NOFILE)) { + if (url_fopen(&avf->pb, filename, URL_WRONLY) < 0) { + mp_msg(MSGT_VO, MSGL_ERR, "vo-lavf: could not open '%s'\n", + filename); + free_avf(); + return -1; + } + } + if (av_write_header(avf) < 0) { + mp_msg(MSGT_VO, MSGL_ERR, "vo-lavf: could not write header\n"); + free_avf(); + return -1; + }

I consider a goto vastly preferable over this code-quituplication...

Nicolas George

8:32 p.m.

Le septidi 17 brumaire, an CCXIX, Reimar Döffinger a écrit :

...

I'd prefer you didn't, I'd prefer to save myself having to think if there might be any compatibilty issue with some calling conventions.

Ok. What about adding a pts field to mp_image_t?

...

Also, while it is a hack there is already a vo_pts variable.

Unfortunately, it is fed by the timestamp from the demuxer, while video filters can add or remove frames.

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Lastly, I miss the most important information: why? What is the big advantage over using mencoder?

Half the times when someone ask something about mencoder, the answer is "mencoder is unmaintained, use ffmpeg instead". And this is not wrong: I remember the time it took to bring ASS support from mplayer to mencoder, and I understand that there are still features that are not in sync. And let us not forget that mencoder can not mux keyframes in most formats.

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