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mirror of https://github.com/rofafor/vdr-plugin-femon.git synced 2023-10-10 13:36:53 +02:00
vdr-plugin-femon/femonmpeg.c
Rolf Ahrenberg 8bf429b381 Added initial support for H.264 and HE-AAC.
Fixed detection of false positives in audio/video streams.
Refactored source code.
2008-11-09 13:43:27 +02:00

185 lines
5.4 KiB
C

/*
* Frontend Status Monitor plugin for the Video Disk Recorder
*
* See the README file for copyright information and how to reach the author.
*
*/
#include "femontools.h"
#include "femonmpeg.h"
#define IS_MPEG_AUDIO(buf) (((buf)[0] == 0xFF) && ((buf)[1] & 0xF0))
#define IS_SEQUENCE_HEADER(buf) (((buf)[0] == 0x00) && ((buf)[1] == 0x00) && ((buf)[2] == 0x01) && ((buf)[3] == 0xB3))
static unsigned int 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
}
};
static unsigned int samplerates[2][4] =
{
{22050, 24000, 16000, -1}, // MPEG-2
{44100, 48000, 32000, -1} // MPEG-1
};
static eAudioCodec 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
};
bool getMPEGAudioInfo(uint8_t *buf, int len, audio_info_t *info)
{
// MPEG audio detection, search for syncword
if ((len < 4) || !IS_MPEG_AUDIO(buf))
return false;
int mpegIndex = (buf[1] & 0x08) >> 3; // MPEG-2=0, MPEG-1=1
int layerIndex = 3 - ((buf[1] & 0x06) >> 1); // I=11, II=10, III=01
int bitrateIndex = (buf[2] & 0xF0) >> 4;
int frequency = (buf[2] & 0x0C) >> 2;
int channelMode = (buf[3] & 0xC0) >> 6;
info->codec = formats[mpegIndex][layerIndex];
switch (channelMode) {
case 0:
info->channelMode = AUDIO_CHANNEL_MODE_STEREO;
break;
case 1:
info->channelMode = AUDIO_CHANNEL_MODE_JOINT_STEREO;
break;
case 2:
info->channelMode = AUDIO_CHANNEL_MODE_DUAL;
break;
case 3:
info->channelMode = AUDIO_CHANNEL_MODE_SINGLE;
break;
default:
info->channelMode = AUDIO_CHANNEL_MODE_INVALID;
break;
}
switch (bitrateIndex) {
case 0:
info->bitrate = AUDIO_BITRATE_FREE;
break;
case 0xF:
info->bitrate = AUDIO_BITRATE_RESERVED;
break;
default:
info->bitrate = 1000 * bitrates[mpegIndex][layerIndex][bitrateIndex];
break;
}
switch (frequency) {
case 3:
info->samplingFrequency = AUDIO_SAMPLING_FREQUENCY_RESERVED;
break;
default:
info->samplingFrequency = samplerates[mpegIndex][frequency];
break;
}
return true;
}
bool getMPEGVideoInfo(uint8_t *buf, int len, video_info_t *info)
{
// MPEG-2 video detection, search for sequence header
if ((len < 7) || !IS_SEQUENCE_HEADER(buf))
return false;
// Parse header
uint8_t *data = buf + 4;
info->codec = VIDEO_CODEC_MPEG2;
info->width = ((data[1] & 0xF0) >> 4) | (data[0] << 4);
info->height = ((data[1] & 0x0F) << 8) | (data[2]);
switch ((data[3] & 0xF0) >> 4) {
case 1:
info->aspectRatio = VIDEO_ASPECT_RATIO_1_1;
break;
case 2:
info->aspectRatio = VIDEO_ASPECT_RATIO_4_3;
break;
case 3:
info->aspectRatio = VIDEO_ASPECT_RATIO_16_9;
break;
case 4:
info->aspectRatio = VIDEO_ASPECT_RATIO_2_21_1;
break;
case 5 ... 15:
default:
info->aspectRatio = VIDEO_ASPECT_RATIO_RESERVED;
break;
}
// Video scan should be read from progressive_sequence field in sequence extension
switch (data[3] & 0x0F) {
case 1:
info->frameRate = 24000 / 1001.0;
info->scan = VIDEO_SCAN_PROGRESSIVE;
info->format = VIDEO_FORMAT_UNKNOWN;
break;
case 2:
info->frameRate = 24.0;
info->scan = VIDEO_SCAN_PROGRESSIVE;
info->format = VIDEO_FORMAT_UNKNOWN;
break;
case 3:
info->frameRate = 25.0;
info->scan = VIDEO_SCAN_UNKNOWN; // interlaced or progressive
info->format = VIDEO_FORMAT_PAL;
break;
case 4:
info->frameRate = 30000 / 1001.0;
info->scan = VIDEO_SCAN_UNKNOWN; // interlaced or progressive
info->format = VIDEO_FORMAT_NTSC;
break;
case 5:
info->frameRate = 30.0;
info->scan = VIDEO_SCAN_UNKNOWN; // interlaced or progressive
info->format = VIDEO_FORMAT_NTSC;
break;
case 6:
info->frameRate = 50.0;
info->scan = VIDEO_SCAN_PROGRESSIVE;
info->format = VIDEO_FORMAT_PAL;
break;
case 7:
info->frameRate = 60.0;
info->scan = VIDEO_SCAN_PROGRESSIVE;
info->format = VIDEO_FORMAT_NTSC;
break;
case 8:
info->frameRate = 60000 / 1001.0;
info->scan = VIDEO_SCAN_PROGRESSIVE;
info->format = VIDEO_FORMAT_NTSC;
break;
case 9 ... 15:
default:
info->frameRate = 0;
info->scan = VIDEO_SCAN_UNKNOWN;
info->format = VIDEO_FORMAT_UNKNOWN;
break;
}
info->bitrate = 400.0 * (((data[4] << 10) & 0x0003FC00UL) | ((data[5] << 2) & 0x000003FCUL) | (((data[6] & 0xC0) >> 6) & 0x00000003UL));
return true;
}