avcodec: estimate output bitrate for uncompressed video codecs

Allows to get a more realistic total bitrate (and estimated file size)
in avi_write_header. Previously a static default value of 200k was
assumed.

Adds an internal helper function for bitrate guessing.

Signed-off-by: Tobias Rapp <t.rapp@noa-archive.com>
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Tobias Rapp
2017-03-06 08:53:28 +01:00
parent 8db301dead
commit 205b8fd078
49 changed files with 96 additions and 40 deletions

View File

@@ -4343,3 +4343,24 @@ int ff_alloc_a53_sei(const AVFrame *frame, size_t prefix_len,
return 0;
}
int64_t ff_guess_coded_bitrate(AVCodecContext *avctx)
{
AVRational framerate = avctx->framerate;
int bits_per_coded_sample = avctx->bits_per_coded_sample;
int64_t bitrate;
if (!(framerate.num && framerate.den))
framerate = av_inv_q(avctx->time_base);
if (!(framerate.num && framerate.den))
return 0;
if (!bits_per_coded_sample) {
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(avctx->pix_fmt);
bits_per_coded_sample = av_get_bits_per_pixel(desc);
}
bitrate = (int64_t)bits_per_coded_sample * avctx->width * avctx->height *
framerate.num / framerate.den;
return bitrate;
}