[FFmpeg-user] Comparing keyframes of videos for proper alignment

Joel Lopez badassmexican at gmail.com
Wed Apr 29 19:50:09 CEST 2015


Here are the last 3 keyframes of videos I'm trying to verify.  I'm not 100%
certain on what the values mean.


Video 1

[FRAME]

key_frame=0

pkt_pts=754000

pkt_pts_time=251.333333

pkt_dts=754000

pkt_dts_time=251.333333

best_effort_timestamp=754000

best_effort_timestamp_time=251.333333

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183172

pkt_size=138

[/FRAME]

[FRAME]

key_frame=0

pkt_pts=754100

pkt_pts_time=251.366667

pkt_dts=754100

pkt_dts_time=251.366667

best_effort_timestamp=754100

best_effort_timestamp_time=251.366667

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183588

pkt_size=140

[/FRAME]

[FRAME]

key_frame=0

pkt_pts=754200

pkt_pts_time=251.400000

pkt_dts=N/A

pkt_dts_time=N/A

best_effort_timestamp=754200

best_effort_timestamp_time=251.400000

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183450

pkt_size=138

[/FRAME]




Video 2


[FRAME]

key_frame=0

pkt_pts=754000

pkt_pts_time=251.333333

pkt_dts=754000

pkt_dts_time=251.333333

best_effort_timestamp=754000

best_effort_timestamp_time=251.333333

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183172

pkt_size=138

[/FRAME]

[FRAME]

key_frame=0

pkt_pts=754100

pkt_pts_time=251.366667

pkt_dts=754100

pkt_dts_time=251.366667

best_effort_timestamp=754100

best_effort_timestamp_time=251.366667

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183588

pkt_size=140

[/FRAME]

[FRAME]

key_frame=0

pkt_pts=754200

pkt_pts_time=251.400000

pkt_dts=N/A

pkt_dts_time=N/A

best_effort_timestamp=754200

best_effort_timestamp_time=251.400000

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183450

pkt_size=138

[/FRAME]




Video 3


[FRAME]

key_frame=0

pkt_pts=754000

pkt_pts_time=251.333333

pkt_dts=754000

pkt_dts_time=251.333333

best_effort_timestamp=754000

best_effort_timestamp_time=251.333333

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183172

pkt_size=138

[/FRAME]

[FRAME]

key_frame=0

pkt_pts=754100

pkt_pts_time=251.366667

pkt_dts=754100

pkt_dts_time=251.366667

best_effort_timestamp=754100

best_effort_timestamp_time=251.366667

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183588

pkt_size=140

[/FRAME]

[FRAME]

key_frame=0

pkt_pts=754200

pkt_pts_time=251.400000

pkt_dts=N/A

pkt_dts_time=N/A

best_effort_timestamp=754200

best_effort_timestamp_time=251.400000

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183450

pkt_size=138

[/FRAME]


Video 4


[FRAME]

key_frame=0

pkt_pts=754000

pkt_pts_time=251.333333

pkt_dts=754000

pkt_dts_time=251.333333

best_effort_timestamp=754000

best_effort_timestamp_time=251.333333

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183172

pkt_size=138

[/FRAME]

[FRAME]

key_frame=0

pkt_pts=754100

pkt_pts_time=251.366667

pkt_dts=754100

pkt_dts_time=251.366667

best_effort_timestamp=754100

best_effort_timestamp_time=251.366667

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183588

pkt_size=140

[/FRAME]

[FRAME]

key_frame=0

pkt_pts=754200

pkt_pts_time=251.400000

pkt_dts=N/A

pkt_dts_time=N/A

best_effort_timestamp=754200

best_effort_timestamp_time=251.400000

pkt_duration=100

pkt_duration_time=0.033333

pkt_pos=69183450

pkt_size=138

[/FRAME]

On Tue, Apr 28, 2015 at 4:09 PM, Joel Lopez <badassmexican at gmail.com> wrote:

> Hi,
>
> I'm trying to verify that the keyframes of videos we are using are
> properly aligned.  I've found ffprobe to extract the some info but I'm not
> sure what data I should be comparing.
>
> This is so that we can do some adaptive bitrate switching using an SMIL
> file for RTMP, HLS and eventually MPEG-DASH.  I've been reading that they
> keyframes should be a constant 3 seconds apart.  Hopefully someone has some
> experience in this.
>
> [FRAME]
>
> media_type=video
>
> key_frame=1
>
> pkt_pts=0
>
> pkt_pts_time=0.000000
>
> pkt_dts=0
>
> pkt_dts_time=0.000000
>
> best_effort_timestamp=0
>
> best_effort_timestamp_time=0.000000
>
> pkt_duration=100
>
> pkt_duration_time=0.033333
>
> pkt_pos=48
>
> pkt_size=2950
>
> width=1280
>
> height=720
>
> pix_fmt=yuv420p
>
> sample_aspect_ratio=N/A
>
> pict_type=I
>
> coded_picture_number=0
>
> display_picture_number=0
>
> interlaced_frame=0
>
> top_field_first=0
>
> repeat_pict=0
>
> [/FRAME]
>
> [FRAME]
>
> media_type=video
>
> key_frame=0
>
> pkt_pts=100
>
> pkt_pts_time=0.033333
>
> pkt_dts=100
>
> pkt_dts_time=0.033333
>
> best_effort_timestamp=100
>
> best_effort_timestamp_time=0.033333
>
> pkt_duration=100
>
> pkt_duration_time=0.033333
>
> pkt_pos=3136
>
> pkt_size=140
>
> width=1280
>
> height=720
>
> pix_fmt=yuv420p
>
> sample_aspect_ratio=N/A
>
> pict_type=B
>
> coded_picture_number=2
>
> display_picture_number=0
>
> interlaced_frame=0
>
> top_field_first=0
>
> repeat_pict=0
>
> [/FRAME]
>
> [FRAME]
>
> media_type=video
>
> key_frame=0
>
> pkt_pts=200
>
> pkt_pts_time=0.066667
>
> pkt_dts=200
>
> pkt_dts_time=0.066667
>
> best_effort_timestamp=200
>
> best_effort_timestamp_time=0.066667
>
> pkt_duration=100
>
> pkt_duration_time=0.033333
>
> pkt_pos=2998
>
> pkt_size=138
>
> width=1280
>
> height=720
>
> pix_fmt=yuv420p
>
> sample_aspect_ratio=N/A
>
> pict_type=P
>
> coded_picture_number=1
>
> display_picture_number=0
>
> interlaced_frame=0
>
> top_field_first=0
>
> repeat_pict=0
>
> [/FRAME]
>
> [FRAME]
>
> media_type=video
>
> key_frame=0
>
> pkt_pts=300
>
> pkt_pts_time=0.100000
>
> pkt_dts=300
>
> pkt_dts_time=0.100000
>
> best_effort_timestamp=300
>
> best_effort_timestamp_time=0.100000
>
> pkt_duration=100
>
> pkt_duration_time=0.033333
>
> pkt_pos=3414
>
> pkt_size=140
>
> width=1280
>
> height=720
>
> pix_fmt=yuv420p
>
> sample_aspect_ratio=N/A
>
> pict_type=B
>
> coded_picture_number=4
>
> display_picture_number=0
>
> interlaced_frame=0
>
> top_field_first=0
>
> repeat_pict=0
>
> [/FRAME]
>


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