On Wed, Oct 08, 2014 at 10:31:53AM -0700, Vignesh Venkatasubramanian wrote:
> On Wed, Oct 1, 2014 at 10:13 AM, Vignesh Venkatasubramanian
> <vigne...@google.com> wrote:
> > Fix incorrect bandwidth computation in some cases. When the cue end
> > descriptor is null (i.e.) start_time_ns == -1, existing bandwidth
> > computed (if any) should be returned rather than returning 0.
> >
> > Signed-off-by: Vignesh Venkatasubramanian <vigne...@google.com>
> > ---
> > libavformat/matroskadec.c | 96
> > ++++++++++++++++++++++++-----------------------
> > 1 file changed, 49 insertions(+), 47 deletions(-)
> >
> > diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
> > index d856fcc..0e405c7 100644
> > --- a/libavformat/matroskadec.c
> > +++ b/libavformat/matroskadec.c
> > @@ -3188,55 +3188,57 @@ static int64_t
> > webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t
> > }
> > if (desc_end.start_time_ns == -1) {
> > // The prebuffer is larger than the duration.
> > - return (matroska->duration * matroska->time_scale >=
> > prebuffered_ns) ? -1 : 0;
> > - }
> > -
> > - // The prebuffer ends in the last Cue. Estimate how much data was
> > - // prebuffered.
> > - pre_bytes = desc_end.end_offset - desc_end.start_offset;
> > - pre_ns = desc_end.end_time_ns - desc_end.start_time_ns;
> > - pre_sec = pre_ns / nano_seconds_per_second;
> > - prebuffer_bytes +=
> > - pre_bytes * ((temp_prebuffer_ns / nano_seconds_per_second) /
> > pre_sec);
> > -
> > - prebuffer = prebuffer_ns / nano_seconds_per_second;
> > -
> > - // Set this to 0.0 in case our prebuffer buffers the entire video.
> > - bits_per_second = 0.0;
> > - do {
> > - int64_t desc_bytes = desc_end.end_offset -
> > desc_beg.start_offset;
> > - int64_t desc_ns = desc_end.end_time_ns -
> > desc_beg.start_time_ns;
> > - double desc_sec = desc_ns / nano_seconds_per_second;
> > - double calc_bits_per_second = (desc_bytes * 8) / desc_sec;
> > -
> > - // Drop the bps by the percentage of bytes buffered.
> > - double percent = (desc_bytes - prebuffer_bytes) / desc_bytes;
> > - double mod_bits_per_second = calc_bits_per_second * percent;
> > -
> > - if (prebuffer < desc_sec) {
> > - double search_sec =
> > - (double)(matroska->duration * matroska->time_scale) /
> > nano_seconds_per_second;
> > -
> > - // Add 1 so the bits per second should be a little bit
> > greater than file
> > - // datarate.
> > - int64_t bps = (int64_t)(mod_bits_per_second) + 1;
> > - const double min_buffer = 0.0;
> > - double buffer = prebuffer;
> > - double sec_to_download = 0.0;
> > -
> > - int rv = buffer_size_after_time_downloaded(prebuffered_ns,
> > search_sec, bps,
> > - min_buffer,
> > &buffer, &sec_to_download,
> > - s, cues_start);
> > - if (rv < 0) {
> > - return -1;
> > - } else if (rv == 0) {
> > - bits_per_second = (double)(bps);
> > - break;
> > + if (matroska->duration * matroska->time_scale >=
> > prebuffered_ns)
> > + return -1;
> > + bits_per_second = 0.0;
> > + } else {
> > + // The prebuffer ends in the last Cue. Estimate how much data
> > was
> > + // prebuffered.
> > + pre_bytes = desc_end.end_offset - desc_end.start_offset;
> > + pre_ns = desc_end.end_time_ns - desc_end.start_time_ns;
> > + pre_sec = pre_ns / nano_seconds_per_second;
> > + prebuffer_bytes +=
> > + pre_bytes * ((temp_prebuffer_ns / nano_seconds_per_second)
> > / pre_sec);
> > +
> > + prebuffer = prebuffer_ns / nano_seconds_per_second;
> > +
> > + // Set this to 0.0 in case our prebuffer buffers the entire
> > video.
> > + bits_per_second = 0.0;
> > + do {
> > + int64_t desc_bytes = desc_end.end_offset -
> > desc_beg.start_offset;
> > + int64_t desc_ns = desc_end.end_time_ns -
> > desc_beg.start_time_ns;
> > + double desc_sec = desc_ns / nano_seconds_per_second;
> > + double calc_bits_per_second = (desc_bytes * 8) / desc_sec;
> > +
> > + // Drop the bps by the percentage of bytes buffered.
> > + double percent = (desc_bytes - prebuffer_bytes) /
> > desc_bytes;
> > + double mod_bits_per_second = calc_bits_per_second *
> > percent;
> > +
> > + if (prebuffer < desc_sec) {
> > + double search_sec =
> > + (double)(matroska->duration *
> > matroska->time_scale) / nano_seconds_per_second;
> > +
> > + // Add 1 so the bits per second should be a little bit
> > greater than file
> > + // datarate.
> > + int64_t bps = (int64_t)(mod_bits_per_second) + 1;
> > + const double min_buffer = 0.0;
> > + double buffer = prebuffer;
> > + double sec_to_download = 0.0;
> > +
> > + int rv =
> > buffer_size_after_time_downloaded(prebuffered_ns, search_sec, bps,
> > + min_buffer,
> > &buffer, &sec_to_download,
> > + s,
> > cues_start);
> > + if (rv < 0) {
> > + return -1;
> > + } else if (rv == 0) {
> > + bits_per_second = (double)(bps);
> > + break;
> > + }
> > }
> > - }
> >
> > - desc_end = get_cue_desc(s, desc_end.end_time_ns, cues_start);
> > - } while (desc_end.start_time_ns != -1);
> > + desc_end = get_cue_desc(s, desc_end.end_time_ns,
> > cues_start);
> > + } while (desc_end.start_time_ns != -1);
> > + }
> > if (bandwidth < bits_per_second) bandwidth = bits_per_second;
> > }
> > return (int64_t)bandwidth;
> > --
> > 2.1.0.rc2.206.gedb03e5
> >
>
> could anyone please look into this? thanks!ive applied this a week ago [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB During times of universal deceit, telling the truth becomes a revolutionary act. -- George Orwell
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