VLSI Solution Oy Evaluation MP3 Player Source Code Documentation

record.h File Reference

ADPCM Recording. More...

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Functions
unsigned char	Record ()
	Record ADPCM.

---

Detailed Description

ADPCM Recording.

Definition in file record.h.

---

Function Documentation

unsigned char Record (   )

Record ADPCM. Recording is probably the least straightforward task with vs10xx, though it's not difficult! The main tasks are: prepare storage space to save recording write a strictly special kind of RIFF header to start of file Warning: the RIFF header must be of the kind stated in datasheet! set sampling speed (Clk/256 divider at SPI_AICTRL0) divider 4 is minimum, giving: 24kHz @ 24.576MHz 42kHz with VS1003, 12.288Mhz xtal, clock multiplier 3.5 divider 12 gives 8kHz @ 24.576Mhz remember to put the correct sample rate in the RIFF header too! set recording level (gain at SPI_AICTRL1) this is digital gain, depends on mic signal level mic/line input impedance is 100 kilo-ohms for VS1002, 100...150mVpp signal level gives best resolution for VS1003, 50...100mVpp is best for mic, 2Vpp for line in 0x1000 is a good first guess for the gain value value 0 sets autogain SPI_VOLUME register controls the loopback volume to earphones reset vs10xx with ADPCM recording mode bit SM_ADPCM (SPI_MODE.12) set for vs1003, to select line in instead of mic, set SPI_MODE.14 monitor ADPCM_DATA_AVAILABLE level in SPI_HDAT1 when data is available, read it into a disksector buffer data is provided in 256-byte (128-word) blocks overfilling buffer resets and aligns automatically to block boundary the fourth byte in a block is always 0x00. check big-endianness / little-endianness for your processor Be relaxed with your timing when reading the SCI registers, give VS10xx a few microseconds time to update the register value after each read. You might need to slower your SPI clock slightly since VS10xx can accept SCI data at slightly faster rate than it is able to provide it. save disksector buffers to disk at end of recording, set SM_OUT_OF_WAV / do a reset of vs10xx insert correct length information in the RIFF HEADER finalize diskfile (write FAT records and dir entry) Remarks: in this test version, recording more is entered by pressing the LEFT button while booting and then releasing it after "Filesys OK" message this version can only record continuous fragments, If a fragment boundary is reached, recording will stop. The main player loop is constructed so that in this situation record() is called again to continue recording to a new file. Most MMC handling issues (bugs) seem to be corrected now but the filesystem code might still overwrite files or corrupt FAT tables in some type of MMC card. You are warned, this is beta quality software :) Todo: VS1002 recording: only new sample rate values need to be calculated. This recording function can only save data into a continuous area on disk. The Fragment Table fragment[] is used in a special way for recording (to save microcontroller RAM space). fragment[0].start is the first disk sector of the file fragment[0].length will contain the number of disk sectors for the file. Bug: In case of fragmented filesystem, this version will not function properly. The RIFF header is constructed in a special way (to make life a bit easier). The most proper way to do it would be to take the header "as is" from the datasheet. But to make life a bit easier, the header here is extended to be 512 bytes (a disk sector) long by adding zeroes to the 'fact' chunk. 'junk' chunks should not be used. The preliminary header is written to disk prior to recording (to give some chances of recovering track in case of battery failure etc). It has a ridiculously long track length. After recording, the header must be rewritten with correct track length. Todo: second FAT table update Definition at line 101 of file record.c. References AvailableProcessorTime(), Temp::b, DiskBlock::Raw::buf, Temp::c, dataBufPtr, Delay(), diskSect, displayValue, DS_STATIC, fatSectorsPerCluster, fragment, freeSector, GREEN_LED, Temp::i, InitDisplay(), KEY_BUTTON, Temp::l, Address::l, LED_OFF, LED_ON, fragmentEntry::length, Mp3DeselectControl, Mp3ReadRegister(), Mp3Reset(), Mp3WriteRegister, playingState, PS_NEXT_SONG, PS_RECORDING, DiskBlock::raw, ReadDiskSector(), RIFFHeader0, RIFFHeader504, ScanForFreeSector(), sectorAddress, SPI_AICTRL0, SPI_AICTRL1, SPI_CLOCKF, SPI_DECODE_TIME, SPI_HDAT0, SPI_HDAT1, SPI_MODE, fragmentEntry::start, temp, UI_TITLE, uiMode, WriteClusterChain(), and WriteDiskSector(). Referenced by main(). { xdata unsigned char blockNumber; xdata unsigned long sectorCount; xdata unsigned long lastSector; bit stopRecording = 0; bit continueRecording = 0; char oldlevel=0; blockNumber = 0; sectorCount = 1; playingState = PS_RECORDING; //Inform the world that rec mode is on. // Kick vs10xx into action! /* Set clock register, doubler etc. */ #ifdef VS1003 // Set base xtal 14.7456MHZ (0x0696) | multiplier:fixed 2.5 (0x600) Mp3WriteRegister(SPI_CLOCKF,0x66,0x96); #else Mp3WriteRegister(SPI_CLOCKF,156,204); //for 14.576MHz XTAL #endif //Set sample rate 16khz for VS1003 (6.4kHz for VS1002 :( ) Mp3WriteRegister(SPI_AICTRL0,0x00,0x09); //Set sample rate divider=9 Mp3WriteRegister(SPI_AICTRL1,0x10,0x00); //AutoGain OFF, reclevel 0x1000 Mp3WriteRegister(SPI_MODE,0x18,0x04); //RECORD,NEWMODE,RESET Delay(10); /* Set clock register, doubler etc. */ #ifdef VS1003 // Set base xtal 14.7456MHZ (0x0696) | multiplier:fixed 2.5 (0x600) Mp3WriteRegister(SPI_CLOCKF,0x66,0x96); #else Mp3WriteRegister(SPI_CLOCKF,156,204); //for 14.576MHz XTAL #endif // Locate free space freeSector = 0; ScanForFreeSector(); sectorAddress.l = freeSector; fragment[0].start = freeSector; for (temp.c=0; temp.c<56; temp.c++){ //temp is unsafe global temp variable. diskSect.raw.buf[temp.c] = RIFFHeader0[temp.c]; } for (temp.i=52; temp.i<504; temp.i++){ diskSect.raw.buf[temp.i] = 0; } for (temp.i=504; temp.i<512; temp.i++){ diskSect.raw.buf[temp.i] = RIFFHeader504[temp.i-504]; } lastSector = freeSector; WriteDiskSector(freeSector); /* Get a new free sector */ ScanForFreeSector(); sectorAddress.l = freeSector; dataBufPtr = diskSect.raw.buf; Delay(10); //Sync to incoming audio frame... while (Mp3ReadRegister(SPI_HDAT1)>>8) //lots of data in buffer ; //Wait until buffer level restarts from 0 dataBufPtr = diskSect.raw.buf; //reset dataBufPtr to start of filebuffer blockNumber = 0; ConsoleWrite("\rRecording, push button to stop..."); while((!KEY_BUTTON || (blockNumber!=0) || ((sectorCount)%(fatSectorsPerCluster)!=0)) && (!stopRecording)){ GREEN_LED = LED_ON; //Check for data if (Mp3ReadRegister(SPI_HDAT1) >= 128){ //there is a data block to be read... GREEN_LED = LED_OFF; blockNumber++; //dataBufPtr should point inside disk buffer, this should never fail: if (dataBufPtr>(diskSect.raw.buf+511)){ ConsoleWrite("\rBuffer indexing error. Stop.\r"); while(1); //stop } //Get the data for (temp.c=0;temp.c<128;temp.c++){ data unsigned int i; i = Mp3ReadRegister(SPI_HDAT0); *dataBufPtr++ = (i>>8); *dataBufPtr++ = (i&0xff); } { //Do basic SOUND LEVEL BAR calculation based on the 1 linear //sample in block[0] and [1] signed int soundlevel; // the user interface (level bar) calculation if (uiMode == UI_TITLE){ soundlevel = (signed char)diskSect.raw.buf[1]<<7; soundlevel |= diskSect.raw.buf[0]>>1; if (soundlevel<0) soundlevel = -soundlevel; displayValue=0; while (soundlevel>31){ displayValue++; soundlevel>>=1; } if (soundlevel>19) displayValue++; if (soundlevel>12) displayValue++; if (soundlevel>6) displayValue++; displayValue-=3; displayValue*=13; if (oldlevel>displayValue){ displayValue=oldlevel-3; } oldlevel=displayValue; } AvailableProcessorTime(); }//SOUND LEVEL BAR calculation }//if there was data to read //Release SCI chip select, we might want to use MMC card Mp3DeselectControl(); if (blockNumber==2){ //2 blocks (512 bytes) received, write to disk... //If we update the SPI_DECODE_TIME, it will show on player screen :) //we can do it, no problem. Here is the calculation for 16khz; //for 16kHz sample rate, 505 samples/block, 8 disk sectors are //exactly 505 milliseconds. temp.l = (sectorCount/8) * 505; temp.l /= 1000; Mp3WriteRegister(SPI_DECODE_TIME,temp.b.b1,temp.b.b0); Mp3DeselectControl(); blockNumber = 0; sectorCount++; WriteDiskSector(sectorAddress.l); lastSector = freeSector; ScanForFreeSector(); //this would be the proper way to go... sectorAddress.l = freeSector; //keep all variables in proper values dataBufPtr = diskSect.raw.buf; //reset data buffer pointer if (freeSector!=(lastSector+1)){ //end of continuous space, must break! stopRecording = 1; ConsoleWrite("\nFragment end - can't continue recording!\n"); InitDisplay(DS_STATIC,"FRAGMENT"," LIMIT!!",0); continueRecording = 1; } } displayValue = 0; }//while not button - stop recording when BUTTON is pressed fragment[0].length = sectorCount; //Enter size information to RIFF header.. { xdata addressType size; ReadDiskSector(fragment[0].start); //Patch in number of samples size.l = (sectorCount-1)*1010; diskSect.raw.buf[48] = size.b.b0; diskSect.raw.buf[49] = size.b.b1; diskSect.raw.buf[50] = size.b.b2; diskSect.raw.buf[51] = size.b.b3; //Patch in size of RIFF chunk... size.l = (sectorCount*512)-8; diskSect.raw.buf[4] = size.b.b0; diskSect.raw.buf[5] = size.b.b1; diskSect.raw.buf[6] = size.b.b2; diskSect.raw.buf[7] = size.b.b3; //Patch in size of DATA chunk... size.l = (sectorCount*512)-512; diskSect.raw.buf[508] = size.b.b0; diskSect.raw.buf[509] = size.b.b1; diskSect.raw.buf[510] = size.b.b2; diskSect.raw.buf[511] = size.b.b3; WriteDiskSector(sectorAddress.l); } ConsoleWrite("Registering... FStart:"); ConsolePutUInt(fragment[0].start); ConsoleWrite("Registering... Size:"); ConsolePutUInt(fragment[0].length); //Create FAT records. fragment[1].start = 0x0fffffff; //fragment 0 is the only fragment WriteClusterChain(); //register newly created file in FAT FS sectorAddress.l = 0; //force sector reload for next access Mp3Reset(); if (continueRecording) return PS_RECORDING; return PS_NEXT_SONG; } Here is the call graph for this function:

---

All software copyright 2000-2004 VLSI Solution OY. Redistribution of these software modules are limited to promotional use only and only with the VS1011 / VS1002 / VS1003 MP3-Evakit evaluation boards. Free or commercial use of these software modules in MP3 players is ok if the product includes MP3 decoder chip(s) from VLSI. You can request the complete (compilable) package from mp3@vlsi.fi