While decoding an flv video av_codec_decode_video2 fails to decode the 2nd frame at first but succeeds after seeking.

[tr3wory]

Summary of the bug:

I have a bunch of flv videos recorded with our wowza server with the same problem:
When I try to decode the frames from beginnig to end, the avcodec_decode_video2 skips the 2nd frame (and only that).
But if I seek back to the beginnig it will decode the second frame properly.

How to reproduce:
Attached a simple example code and sample video demonstrating the problem.
See the asserts in line 78 and 96.

Used version:
ffmpeg version N-75147-g9d742d2 Copyright (c) 2000-2015 the FFmpeg developers

built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04)
configuration: --prefix='~/BUILD/ffmpeg'
libavutil 55. 1.100 / 55. 1.100
libavcodec 57. 1.100 / 57. 1.100
libavformat 57. 0.100 / 57. 0.100
libavdevice 57. 0.100 / 57. 0.100
libavfilter 6. 1.100 / 6. 1.100
libswscale 4. 0.100 / 4. 0.100
libswresample 2. 0.100 / 2. 0.100

[tr3wory]

Sample code describing the problem.

[Carl Eugen Hoyos]

How was the input sample made?

[tr3wory]

It was recorded with Wowza:
we record the user's webcam from flash, and stream it to the server.
(I removed the audio stream later with ffmpeg, but the original has the same problem
if I properly skip the audio packets)

It is entirely possible that the file format is not conforming, but since ffmpeg can decode the frames properly after seeking, it looks like there is some problem on the ffmpeg side too.

And I have hundreds of videos like this, so it's a one-off problem.

[Carl Eugen Hoyos]

Replying to tr3wory:

(I removed the audio stream later with ffmpeg, but the original has the same problem
if I properly skip the audio packets)

Please also provide the original file.

[tr3wory]

Original sample file (won't work with the example code)

[tr3wory]

I uploaded the original file. Keep in mind that the sample code won't work with this file because it does not skip the audio packets.