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mpeg.c
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mpeg.c
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/*
* mpeg.c: Frontend Status Monitor plugin for the Video Disk Recorder
*
* See the README file for copyright information and how to reach the author.
*
*/
#include "tools.h"
#include "mpeg.h"
#define IS_EXTENSION_START(buf) (((buf)[0] == 0x00) && ((buf)[1] == 0x00) && ((buf)[2] == 0x01) && ((buf)[3] == 0xB5))
int cFemonMPEG::bitrateS[2][3][16] =
{
{
{0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, -1}, // MPEG-2 Layer I
{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, -1}, // MPEG-2 Layer II/III
{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, -1} // MPEG-2 Layer II/III
},
{
{0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, -1}, // MPEG-1 Layer I
{0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, -1}, // MPEG-1 Layer II
{0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, -1} // MPEG-1 Layer III
}
};
int cFemonMPEG::sampleRateS[2][4] =
{
{22050, 24000, 16000, -1}, // MPEG-2
{44100, 48000, 32000, -1} // MPEG-1
};
eAudioCodec cFemonMPEG::formatS[2][4] =
{
{AUDIO_CODEC_MPEG2_I, AUDIO_CODEC_MPEG2_II, AUDIO_CODEC_MPEG2_III, AUDIO_CODEC_UNKNOWN}, // MPEG-2
{AUDIO_CODEC_MPEG1_I, AUDIO_CODEC_MPEG1_II, AUDIO_CODEC_MPEG1_III, AUDIO_CODEC_UNKNOWN} // MPEG-1
};
cFemonMPEG::cFemonMPEG(cFemonVideoIf *videoHandlerP, cFemonAudioIf *audioHandlerP)
: videoHandlerM(videoHandlerP),
audioHandlerM(audioHandlerP)
{
}
cFemonMPEG::~cFemonMPEG()
{
}
bool cFemonMPEG::processAudio(const uint8_t *bufP, int lenP)
{
cFemonBitStream bs(bufP, lenP * 8);
if (!audioHandlerM)
return false;
// skip PES header
if (!PesLongEnough(lenP))
return false;
bs.SkipBits(8 * PesPayloadOffset(bufP));
// MPEG audio detection
if (bs.GetBits(12) != 0xFFF) // syncword
return false;
int id = bs.GetBit(); // id: MPEG-2=0, MPEG-1=1
int layer = 3 - bs.GetBits(2); // layer: I=11, II=10, III=01
bs.SkipBit(); // protection bit
int bit_rate_index = bs.GetBits(4); // bitrate index
int sampling_frequency = bs.GetBits(2); // sampling frequency
bs.SkipBit(); // padding bit
bs.SkipBit(); // private pid
int mode = bs.GetBits(2); // mode
audioHandlerM->SetAudioCodec(formatS[id][layer]);
switch (mode) {
case 0:
audioHandlerM->SetAudioChannel(AUDIO_CHANNEL_MODE_STEREO);
break;
case 1:
audioHandlerM->SetAudioChannel(AUDIO_CHANNEL_MODE_JOINT_STEREO);
break;
case 2:
audioHandlerM->SetAudioChannel(AUDIO_CHANNEL_MODE_DUAL);
break;
case 3:
audioHandlerM->SetAudioChannel(AUDIO_CHANNEL_MODE_SINGLE);
break;
default:
audioHandlerM->SetAudioChannel(AUDIO_CHANNEL_MODE_INVALID);
break;
}
switch (bit_rate_index) {
case 0:
audioHandlerM->SetAudioBitrate(AUDIO_BITRATE_FREE);
break;
case 0xF:
audioHandlerM->SetAudioBitrate(AUDIO_BITRATE_RESERVED);
break;
default:
audioHandlerM->SetAudioBitrate(1000 * bitrateS[id][layer][bit_rate_index]);
break;
}
switch (sampling_frequency) {
case 3:
audioHandlerM->SetAudioSamplingFrequency(AUDIO_SAMPLING_FREQUENCY_RESERVED);
break;
default:
audioHandlerM->SetAudioSamplingFrequency(sampleRateS[id][sampling_frequency]);
break;
}
return true;
}
bool cFemonMPEG::processVideo(const uint8_t *bufP, int lenP)
{
cFemonBitStream bs(bufP, lenP * 8);
if (!videoHandlerM)
return false;
// skip PES header
if (!PesLongEnough(lenP))
return false;
bs.SkipBits(8 * PesPayloadOffset(bufP));
// MPEG-2 video detection, search for start code
if (bs.GetBits(32) != 0x000001B3) // sequence header
return false;
int scan = VIDEO_SCAN_UNKNOWN;
int format = VIDEO_FORMAT_UNKNOWN;
int aspect = VIDEO_ASPECT_RATIO_RESERVED;
int horizontal_size = bs.GetBits(12); // horizontal size value
int vertical_size = bs.GetBits(12); // vertical size value
switch (bs.GetBits(4)) { // aspect ratio information
case 1:
aspect = VIDEO_ASPECT_RATIO_1_1;
break;
case 2:
aspect = VIDEO_ASPECT_RATIO_4_3;
break;
case 3:
aspect = VIDEO_ASPECT_RATIO_16_9;
break;
case 4:
aspect = VIDEO_ASPECT_RATIO_2_21_1;
break;
case 5 ... 15:
default:
aspect = VIDEO_ASPECT_RATIO_RESERVED;
break;
}
double frame_rate = 0;
switch (bs.GetBits(4)) { // frame rate code
case 1:
frame_rate = 24000 / 1001.0;
format = VIDEO_FORMAT_UNKNOWN;
break;
case 2:
frame_rate = 24.0;
format = VIDEO_FORMAT_UNKNOWN;
break;
case 3:
frame_rate = 25.0;
format = VIDEO_FORMAT_PAL;
break;
case 4:
frame_rate = 30000 / 1001.0;
format = VIDEO_FORMAT_NTSC;
break;
case 5:
frame_rate = 30.0;
format = VIDEO_FORMAT_NTSC;
break;
case 6:
frame_rate = 50.0;
format = VIDEO_FORMAT_PAL;
break;
case 7:
frame_rate = 60.0;
format = VIDEO_FORMAT_NTSC;
break;
case 8:
frame_rate = 60000 / 1001.0;
format = VIDEO_FORMAT_NTSC;
break;
case 9 ... 15:
default:
frame_rate = 0;
format = VIDEO_FORMAT_UNKNOWN;
break;
}
int bit_rate = bs.GetBits(18); // bit rate value
bs.SkipBit(); // marker bit
bs.SkipBits(10); // vbv buffer size value
bs.SkipBit(); // constrained parameters value
if (bs.GetBit()) // load intra quantizer matrix
bs.SkipBits(8 * 64); // intra quantizer matrix
if (bs.GetBit()) // load non-intra quantizer matrix
bs.SkipBits(8 * 64); // non-intra quantizer matrix
if (bs.GetBits(32) != 0x000001B5) { // extension start
bs.SkipBits(4); // extension start code identifier
bs.SkipBits(8); // profile and level indicator
scan = bs.GetBit() ? VIDEO_SCAN_PROGRESSIVE :
VIDEO_SCAN_INTERLACED; // progressive sequence
bs.SkipBits(2); // chroma format
horizontal_size |= (bs.GetBits(2) << 12); // horizontal size extension
vertical_size |= (bs.GetBits(2) << 12); // vertical size extension
bit_rate |= (bs.GetBits(12) << 18); // bit rate extension
bs.SkipBit(); // marker bit
bs.SkipBits(8); // vpv buffer size extension
bs.SkipBit(); // low delay
bs.SkipBits(2); // frame rate extension n
bs.SkipBits(5); // frame rate extension d
if ((bs.GetBits(32) != 0x000001B5) && // extension start code
(bs.GetBits(4) == 0x0010)) { // sequence display extension id
switch (bs.GetBits(3)) { // video format
case 0x000:
format = VIDEO_FORMAT_COMPONENT;
break;
case 0x001:
format = VIDEO_FORMAT_PAL;
break;
case 0x010:
format = VIDEO_FORMAT_NTSC;
break;
case 0x011:
format = VIDEO_FORMAT_SECAM;
break;
case 0x100:
format = VIDEO_FORMAT_MAC;
break;
case 0x101:
format = VIDEO_FORMAT_UNKNOWN;
break;
case 0x110:
case 0x111:
format = VIDEO_FORMAT_RESERVED;
break;
default:
format = VIDEO_FORMAT_INVALID;
break;
}
}
}
videoHandlerM->SetVideoCodec(VIDEO_CODEC_MPEG2);
videoHandlerM->SetVideoSize(horizontal_size, vertical_size);
videoHandlerM->SetVideoBitrate(400.0 * (double)(bit_rate));
videoHandlerM->SetVideoFramerate(frame_rate);
videoHandlerM->SetVideoScan(eVideoScan(scan));
videoHandlerM->SetVideoAspectRatio(eVideoAspectRatio(aspect));
videoHandlerM->SetVideoFormat(eVideoFormat(format));
return true;
}