Shouldn't all GOPs be closed?

[Zoltan]

Hi, so far I believed that all GOPs should be closed for editing for an SVCD. The reason for this AFAIK is that FF and RW functions display I frames and without closed GOPs and available sequence headers the are not easy to locate. Actually my player plays both closed and open GOP videos.

I have just discovered that CCE_Project_file.ecl does not specify closing GOPs. Details below. See "all_closed_gop=0".

Any reason/idea?
Thanks,
Z

; Cinema Craft Encoder SP -- Encoder Control List

[item]
title=AviSynth_Script_file.avs
vid_out=1
vaf_out=1
aud_out=0
vid_file0=D:\D2S\Encoded_Video_CCE_PAL.mpv
vid_file1=D:\D2S\Encoded_Video_CCE_PAL.mpv
vaf_file=D:\D2S\CCE_Video_Information_File.vaf
aud_file=D:\D2S\Encoded_Video_CCE_PAL.mpv.mp2
file_focused=0
encode_mode=0
packet_size=4096
timecode=0x1000000
width=480
height=576
vmode=2
frame_rate_idx=3
cbr_brate=6000
opv_q_factor=60
opv_brate_min=2000
opv_brate_max=9000
vbr_brate_avg=1600
vbr_brate_min=1000
vbr_brate_max=2000
vbr_bias=30
vbr_pass=4
quality_prec=17
use_filter=1
filter_val=2
seq_endcode=1
dvd=0
half_width=0
half_height=0
fast_mode=0
progressive=0
alternate_scan=0
non_linear=0
top_first=1
lum_level=1
intra_dc_prec=1
aspect_ratio=2
gop_m=3
gop_nm=4
gop_hdr=12
seq_hdr=1
all_closed_gop=0
fix_gop_length=0
mpeg1=0
mpeg1_cps=1
samples_per_sec=44100
stereo=2
brate_idx=7
crc=1

[file]
name=D:\D2S\AviSynth_Script_file.avs
type=0
frame_first=0
frame_last=43690
encode_first=0
encode_last=43690

[markrb]

I moved this to advanced since it's over my head. :D

Mark

[Doom9]

I'm coming from a DVD authoring angle here... closed gops are a requirement in the following 2 cases:

1) you plan to edit your m2vs afterwards
2) you're dealing with a multiangle scene

In all other cases open gops should be fine. And since we're playing our SVCDs on DVD players I'd presume that the same constraints apply as for DVDs. And since we don't have multiangles on SVCDs and normally don't edit the mpeg2 files (except for splitting which seems to be no problem, and the m2vs on dvds are also split during the muxing phase) there shouldn't be a problem with open GOPs on SVCDs.

[Zoltan]

So FF and RW does not need closed GOP.
Thanks for the quick answer, Doom9!
Z