On 17.09.2012 14:17, Придворов Андрей (Pridvorov Andrey) wrote:
I analyzed the streams.
I-frame have Sequence Parameter Set always, and NAL type = 7.
My suggestion:
....
int FrameTypeOffset = i + 6;//Offset to Sequence parameter set
if (FrameTypeOffset >= TS_SIZE) // the byte to check is in the next TS
packet
i = SkipPackets(Data, Length, Processed, FrameTypeOffset);
newFrame = true;
uchar FrameType = Data[FrameTypeOffset]&0x1F;//NAL Unit Type is last 5 bit
independentFrame = FrameType == 0x07;//NAL Unit Type = 7 if I-frame
...
It's works all time.
That was a very good pointer in the right direction.
However, we can't just blindly look at Data[i + 6], but rather have
to search for a NALU start code after the Access Unit Delimiter.
The attached patch changes cFrameDetector::Analyze() accordingly,
and it still works with the HD channels I have access to, and also
the sample you sent me earlier.
Please try whether this patch works with all the HD channels you can
receive.
I would also appreciate if as many other VDR users as possible applied
this patch and tested it, so that we can be sure it works before I release
the next developer version.
Klaus
-----Original Message-----
From: vdr-bounces@xxxxxxxxxxx [mailto:vdr-bounces@xxxxxxxxxxx] On Behalf Of
Klaus Schmidinger
Sent: Friday, September 14, 2012 8:40 AM
To: vdr@xxxxxxxxxxx
Subject: Re: vdr-1.7.29 + h264 MBAFF
On 13.09.2012 23:15, Reinhard Nissl wrote:
Hi,
Am 13.09.2012 12:25, schrieb Klaus Schmidinger:
On 12.09.2012 17:19, Придворов Андрей (Pridvorov Andrey) wrote:
Progress display show correct time, but at the end play freeze.
Other player (on MS windows) play correct.
Try http://rghost.ru/40326577
It looks like the frame type is 0xF0 for *all* frames of this
stream.
But when I play it on my TT S2-6400 card, even though I can move an
editing mark to every single frame, only every 10th or so frame
is actually
displayed on the tv.
So my guess is, the frame types are not set correctly in this
stream.
0xF0 seems bogus to me. So far I have seen only 0x10, 0x30 and
0x50 (IIRC).
Well, testing for the whole byte is not according to the specs, as only
the upper 3 bits denote primary_pic_type. So the typical primary_pic_types
are 0, 2 and 4 while 0xF0 yields 7.
So I guess in cFrameDetector::Analyze() it should then be
uchar FrameType = Data[FrameTypeOffset] &
0xE0;
independentFrame = FrameType == 0x00;
which doesn't make much of a difference for this particular case, but
at least would look at only the valid bits.
primary_pic_type tells you, which slice_types (among I, SI, P, SP, B) may
be used to describe the picture, so one can derive the MPEG1/2 I, B and P
picture type meaning from it for the typical cases.
primary_pic_type 7 indicates that all slice types may be used to describe
the picture, so the best match for a MPEG1/2 picture type would be a B
picture.
Hence, the byte value 0xF0 is valid and correct, but doesn't help
anyfurther to find independent pictures.
I really wonder what kind of crack the people who came up with this stuff
have smoked. Why didn't they just put in there a simple, straightforward
bit that says "an independent picture starts here"?
Klaus
-----Original Message-----
From: vdr-bounces@xxxxxxxxxxx [mailto:vdr-bounces@xxxxxxxxxxx]
On Behalf Of
Klaus Schmidinger
Sent: Thursday, September 13, 2012 1:33 AM
To: vdr@xxxxxxxxxxx
Subject: Re: vdr-1.7.29 + h264 MBAFF
On 12.09.2012 16:06, Придворов Андрей (Pridvorov Andrey) wrote:
Hi.
I have trouble with some h264 HD channels.
It have MBAFF scan type, live tv on vdr works, but no recordings.
Recorded file have 0 size.
But, if in remux.c, in int cFrameDetector::Analyze(const uchar
*Data, int
Length)
change
independentFrame = FrameType == 0x10
to
independentFrame = (FrameType == 0x10 || FrameType == 0xf0)
Than all recordings fine.
Is this correct?
I tend to doubt that.
What about the progress display when you replay such a recording?
Does it show the correct times?
Can you make a short recording available for further
investigation?
Klaus
--- remux.c 2012/09/14 09:06:14 2.65
+++ remux.c 2012/09/18 09:11:24
@@ -843,7 +843,8 @@
int cFrameDetector::Analyze(const uchar *Data, int Length)
{
- int SeenPayloadStart = false;
+ bool SeenPayloadStart = false;
+ bool SeenAccessUnitDelimiter = false;
int Processed = 0;
newFrame = independentFrame = false;
while (Length >= TS_SIZE) {
@@ -970,12 +971,16 @@
scanner = EMPTY_SCANNER;
if (synced && !SeenPayloadStart && Processed)
return Processed; // flush everything before this new frame
+ SeenAccessUnitDelimiter = true;
+ }
+ else if (SeenAccessUnitDelimiter && scanner == 0x00000001) { // NALU start
+ SeenAccessUnitDelimiter = false;
int FrameTypeOffset = i + 1;
if (FrameTypeOffset >= TS_SIZE) // the byte to check is in the next TS packet
i = SkipPackets(Data, Length, Processed, FrameTypeOffset);
newFrame = true;
- uchar FrameType = Data[FrameTypeOffset] & 0xE0;
- independentFrame = FrameType == 0x00;
+ uchar FrameType = Data[FrameTypeOffset] & 0x1F;
+ independentFrame = FrameType == 0x07;
if (synced) {
if (framesPerPayloadUnit < 0) {
payloadUnitOfFrame = (payloadUnitOfFrame + 1) % -framesPerPayloadUnit;
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