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[mmalcodec] Remove dropping logic. It only seems to make things worse
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We get frequent reports of stuttery playback especially with live tv,
the PVR channel preview window and overlays with mmal.

The problem is whenever the dropping code is triggered it makes the
problem worse.

I suspect this is an issue with the asynchronous mmal decoder which has
a large input buffer (~2MB) which for a low bitrate stream can contain
a couple of seconds of video. We end up dropping a very large number of
frames which tends to upset dvdplayer more.

Seeing as dropping frames has marginal benefit - the work is done on
the gpu which isn't the bottleneck, and discarding frames doesn't help
the processing on the arm side sigificantly, just don't do it.
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@popcornmix
popcornmix committed May 8, 2015
1 parent 58171c8 commit 2c1c4fb
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Showing 2 changed files with 21 additions and 59 deletions.
78 changes: 21 additions & 57 deletions xbmc/cores/dvdplayer/DVDCodecs/Video/MMALCodec.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -97,7 +97,6 @@ CMMALVideo::CMMALVideo()
CLog::Log(LOGDEBUG, "%s::%s %p", CLASSNAME, __func__, this);
pthread_mutex_init(&m_output_mutex, NULL);

m_drop_state = false;
m_decoded_width = 0;
m_decoded_height = 0;

Expand All @@ -108,7 +107,6 @@ CMMALVideo::CMMALVideo()
m_interlace_method = VS_INTERLACEMETHOD_NONE;
m_startframe = false;
m_decoderPts = DVD_NOPTS_VALUE;
m_droppedPics = 0;

m_dec = NULL;
m_dec_input = NULL;
Expand Down Expand Up @@ -257,15 +255,6 @@ void CMMALVideo::dec_output_port_cb(MMAL_PORT_T *port, MMAL_BUFFER_HEADER_T *buf
if (buffer->length > 0)
{
assert(!(buffer->flags & MMAL_BUFFER_HEADER_FLAG_DECODEONLY));
if (m_drop_state)
{
pthread_mutex_lock(&m_output_mutex);
m_droppedPics++;
pthread_mutex_unlock(&m_output_mutex);
if (g_advancedSettings.CanLogComponent(LOGVIDEO))
CLog::Log(LOGDEBUG, "%s::%s - dropping %p dts:%.3f pts:%.3f (drop:%d len:%d flags:%x)", CLASSNAME, __func__, buffer, buffer->dts*1e-6, buffer->pts*1e-6, m_drop_state, buffer->length, buffer->flags);
}
else
{
CMMALVideoBuffer *omvb = new CMMALVideoBuffer(this);
if (g_advancedSettings.CanLogComponent(LOGVIDEO))
Expand Down Expand Up @@ -703,7 +692,6 @@ bool CMMALVideo::Open(CDVDStreamInfo &hints, CDVDCodecOptions &options, MMALVide
if (!SendCodecConfigData())
return false;

m_drop_state = false;
m_startframe = false;
m_preroll = !m_hints.stills;
m_speed = DVD_PLAYSPEED_NORMAL;
Expand Down Expand Up @@ -731,30 +719,8 @@ void CMMALVideo::Dispose()

void CMMALVideo::SetDropState(bool bDrop)
{
if (m_drop_state != bDrop)
if (g_advancedSettings.CanLogComponent(LOGVIDEO))
CLog::Log(LOGDEBUG, "%s::%s - m_drop_state(%d)", CLASSNAME, __func__, bDrop);
m_drop_state = bDrop;
if (m_drop_state)
{
while (1)
{
CMMALVideoBuffer *buffer = NULL;
pthread_mutex_lock(&m_output_mutex);
// fetch a output buffer and pop it off the ready list
if (!m_output_ready.empty())
{
buffer = m_output_ready.front();
m_output_ready.pop();
m_droppedPics++;
}
pthread_mutex_unlock(&m_output_mutex);
if (buffer)
ReleaseBuffer(buffer);
else
break;
}
}
if (g_advancedSettings.CanLogComponent(LOGVIDEO))
CLog::Log(LOGDEBUG, "%s::%s - bDrop(%d)", CLASSNAME, __func__, bDrop);
}

int CMMALVideo::Decode(uint8_t* pData, int iSize, double dts, double pts)
Expand Down Expand Up @@ -836,10 +802,6 @@ int CMMALVideo::Decode(uint8_t* pData, int iSize, double dts, double pts)
// set a flag so we can identify primary frames from generated frames (deinterlace)
buffer->flags = MMAL_BUFFER_HEADER_FLAG_USER0;

// Request decode only (maintain ref frames, but don't return a picture)
if (m_drop_state)
buffer->flags |= MMAL_BUFFER_HEADER_FLAG_DECODEONLY;

memcpy(buffer->data, demuxer_content, buffer->length);
demuxer_bytes -= buffer->length;
demuxer_content += buffer->length;
Expand All @@ -862,10 +824,6 @@ int CMMALVideo::Decode(uint8_t* pData, int iSize, double dts, double pts)
{
pthread_mutex_lock(&m_output_mutex);
m_startframe = true;
if (m_drop_state)
{
m_droppedPics += m_deint ? 2:1;
}
pthread_mutex_unlock(&m_output_mutex);
if (m_changed_count_dec != m_changed_count)
{
Expand Down Expand Up @@ -957,16 +915,28 @@ void CMMALVideo::Reset(void)
mmal_port_enable(m_dec_output, dec_output_port_cb_static);
}
// blow all ready video frames
bool old_drop_state = m_drop_state;
SetDropState(true);
while (1)
{
CMMALVideoBuffer *buffer = NULL;
pthread_mutex_lock(&m_output_mutex);
// fetch a output buffer and pop it off the ready list
if (!m_output_ready.empty())
{
buffer = m_output_ready.front();
m_output_ready.pop();
}
pthread_mutex_unlock(&m_output_mutex);
if (buffer)
ReleaseBuffer(buffer);
else
break;
}

pthread_mutex_lock(&m_output_mutex);
while (!m_demux_queue.empty())
m_demux_queue.pop();
m_demux_queue_length = 0;
m_droppedPics = 0;
pthread_mutex_unlock(&m_output_mutex);
if (!old_drop_state)
SetDropState(false);

if (!m_finished)
SendCodecConfigData();
Expand Down Expand Up @@ -1098,12 +1068,6 @@ bool CMMALVideo::ClearPicture(DVDVideoPicture* pDvdVideoPicture)

bool CMMALVideo::GetCodecStats(double &pts, int &droppedPics)
{
pthread_mutex_lock(&m_output_mutex);
pts = m_decoderPts;
droppedPics = m_droppedPics;
m_droppedPics = 0;
pthread_mutex_unlock(&m_output_mutex);
//if (g_advancedSettings.CanLogComponent(LOGVIDEO))
// CLog::Log(LOGDEBUG, "%s::%s - pts:%.0f droppedPics:%d", CLASSNAME, __func__, pts, droppedPics);
return true;
droppedPics= -1;
return false;
}
2 changes: 0 additions & 2 deletions xbmc/cores/dvdplayer/DVDCodecs/Video/MMALCodec.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -107,7 +107,6 @@ class CMMALVideo
bool DestroyDeinterlace();

// Video format
bool m_drop_state;
int m_decoded_width;
int m_decoded_height;
unsigned int m_egl_buffer_count;
Expand Down Expand Up @@ -135,7 +134,6 @@ class CMMALVideo
EINTERLACEMETHOD m_interlace_method;
bool m_startframe;
double m_decoderPts;
unsigned int m_droppedPics;
int m_speed;
bool m_preroll;

Expand Down

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