Keith:
now, I found my decoder is decoding the stream data so slow.
For example, a TV Ad plays only during 1 minite,so it just includes 60*30
frames. but my deocder play it about one frame per second, so need 60*30
seconds to play it. and it does not drop frame! I do not know the reason.
why it do not drop frame to fit real time playing? how to drop frame forcely?
But with the same PC, I can play mpeg2 file correctly.
在2007-04-25，"Keith Winstein" <[EMAIL PROTECTED]> 写道：
Allison,
It would be very difficult to help you debug this without a sample of the
data you're trying to decode.
If I had to guess, it would be that you are getting a transport stream,
because presumably audio is present as well. Such a stream will need to be
demultiplexed before you can send the MPEG-2 Video elementary stream to
libmpeg2. See mpeg2dec.c for an example of how to do this.
Again, that is just a guess. If you really want our help, you will have to
save a sample of the stream to a file and then let us examine it.
-Keith
On Wed, 25 Apr 2007, hdzhang wrote:
> Keith,
>
> I am decoding real-time mpeg2 data, not mpeg file. so I can not provide the
> mpeg2 file.
>
> and I package libmpeg2 codec into windows dirctshow filter, and source code
> as follows:
>
> The Transform function is recall repeatly under real time capture stream data.
>
> It can decoder mpeg2 file correctly ,but real-time data wrong.
>
> HRESULT CMPEG2Decomp::Transform(IMediaSample *pIn, IMediaSample *pOut)
> {
> BYTE *pBufferIn, *pBufferOut;
> long inputLen = pIn->GetActualDataLength();
> HRESULT hr = pIn->GetPointer(&pBufferIn);//pBufferIn is mpeg2 data input.
> it includes header data or one frame data or multi-frame data.
> hr = pOut->GetPointer(&pBufferOut);//pBufferOut is output data
> do
> {
> state = mpeg2_parse (decoder);
> sequence = info->sequence;
> //bMem: 0--memory is uncopied
> // 1--memory is copied
> // 2--need read new memory data
> //
> switch (state)
> {
> case STATE_BUFFER:
> if(bMem==1)
> bMem=2;
> if(bMem==0)
> {
> memcpy(buffer,pBufferIn,inputLen);
> bMem=1;
> mpeg2_buffer (decoder, buffer, buffer + inputLen);
> }
> break;
> case STATE_SEQUENCE:
> mpeg2_custom_fbuf (decoder, 1);
> for (i = 0; i < 3; i++)
> {
> fbuf[i].mbuf[0] = (uint8_t *) malloc
> (info->sequence->width*info->sequence->height + 15);
> fbuf[i].mbuf[1] = (uint8_t *) malloc
> (info->sequence->chroma_width*info->sequence->chroma_height + 15);
> fbuf[i].mbuf[2] = (uint8_t *) malloc
> (info->sequence->chroma_width*info->sequence->chroma_height + 15);
> for (j = 0; j < 3; j++)
> fbuf[i].yuv[j] = (unsigned char *)ALIGN_16
> (fbuf[i].mbuf[j]);
> fbuf[i].used = 0;
> }
> for (i = 0; i < 2; i++)
> {
> current_fbuf = get_fbuf ();
> mpeg2_set_buf (decoder, current_fbuf->yuv,
> current_fbuf);
> }
> break;
> case STATE_PICTURE:
> current_fbuf = get_fbuf ();
> mpeg2_set_buf (decoder, current_fbuf->yuv, current_fbuf);
> break;
> case STATE_SLICE:
> case STATE_END:
> case STATE_INVALID_END:
> if (info->display_fbuf)
> {
> if(pBufferIn != NULL)
> {
> //convert YUV420 data into BMP24 format
> Convert( info->display_fbuf->buf[0],
> info->display_fbuf->buf[1],info->display_fbuf->buf[2],pBufferOut);
>
> pOut->SetActualDataLength(info->sequence->width*info->sequence->height*3);//sets
> the sample's data length.
>
> pOut->SetSyncPoint(TRUE);//output data to display
> }
> }
> if (info->discard_fbuf)
> ((struct fbuf_s *)info->discard_fbuf->id)->used = 0;
> break;
> default:
> break;
> }//end switch
> } while (bMem!=2);
> return S_OK;
> }
>
>
>
> 在2007-04-25，"Keith Winstein" <[EMAIL PROTECTED]> 写道：
>
> Allison,
>
>
>
> I have no idea. Please post the file somewhere or we won't be able to help
>
> you.
>
>
>
> -Keith
>
>
>
> On Wed, 25 Apr 2007, hdzhang wrote:
>
>
>
>> Keith,
>
>>
>
>> I used a "MPEG push demultiplexer".
>
>>
>
>> Is data from this demultiplexer TS or ES?
>
>>
>
>>
>
>> Allison
>
>>
>
>> 在2007-04-25，"Keith Winstein" <[EMAIL PROTECTED]> 写道：
>
>>
>
>> Hello,
>
>>
>
>> Can you please post a section of this file on the Internet so we can
>
>> examine it? Maybe you've got a transport stream instead of an elementary
>
>> stream or something like that.
>
>>
>
>> -Keith
>
>>
>
>> On Wed, 25 Apr 2007, hdzhang wrote:
>
>>
>
>>> hi, now I receive mpeg2 data from satelite receiver.
>
>>> But when I run mpeg2 codec ,I found it only can recognize STATE_BUFFER, can
>>> not recognize STATE_SEQUENCE or STATE_PICTURE. So it can not decoder
>>> picture correctly.
>
>>> Why ? is the format of data received by satelite receiver not the same with
>>> data from MPEG2 file?
>
>>>
>
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