apps/plugins/mpegplayer/libmpeg2/README.rockbox


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Library: libmpeg2 from mpeg2dec-0.4.0b (Released 2004-01-21)
Imported: 2006-08-06 by Dave Chapman


This directory contains a local version of libmpeg2 imported into
Rockbox for MPEG video decoding.


LICENSING INFORMATION

mpeg2dec and libmpeg2 are licensed under Version 2 of the GNU General
Public License.


IMPORT DETAILS

The following files were imported from the mpeg2dec-0.4.0b
distribution.  Minor changes were made to enable compilation in
Rockbox and TABs were replaced by spaces to comply with the Rockbox
coding guidelines.

AUTHORS
README
SOURCES
attributes.h
cpu_accel.c
cpu_state.c
decode.c
header.c
idct.c
motion_comp.c
mpeg2.h
mpeg2_internal.h
slice.c
video_out.h
vlc.h

The following files are new, but based on code in mpeg2dec.

Makefile
mpegplayer.c
video_out_rockbox.c
mpeg2dec_config.h
alloc.c
/***************************************************************************
*             __________               __   ___.
*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
*                     \/            \/     \/    \/            \/
* $Id$
*
* Plugin for video playback
* Reads raw image data + audio data from a file
* !!!!!!!!!! Code Police free zone !!!!!!!!!!
*
* Copyright (C) 2003-2004 J�rg Hohensohn aka [IDC]Dragon
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/


/****************** imports ******************/

#include "plugin.h"
#include "sh7034.h"
#include "system.h"
#include "../apps/recorder/widgets.h" // not in search path, booh

#ifndef SIMULATOR // not for simulator by now
#ifdef HAVE_LCD_BITMAP // and definitely not for the Player, haha

/* variable button definitions */
#if CONFIG_KEYPAD == RECORDER_PAD
#define VIDEO_STOP_SEEK BUTTON_PLAY
#define VIDEO_RESUME BUTTON_PLAY
#define VIDEO_DEBUG BUTTON_F1
#define VIDEO_CONTRAST_DOWN BUTTON_F2
#define VIDEO_CONTRAST_UP BUTTON_F3

#elif CONFIG_KEYPAD == ONDIO_PAD
#define VIDEO_STOP_SEEK_PRE BUTTON_MENU
#define VIDEO_STOP_SEEK (BUTTON_MENU | BUTTON_REL)
#define VIDEO_RESUME BUTTON_RIGHT
#define VIDEO_CONTRAST_DOWN (BUTTON_MENU | BUTTON_DOWN)
#define VIDEO_CONTRAST_UP (BUTTON_MENU | BUTTON_UP)

#endif
/****************** constants ******************/

#define INT_MAX ((int)(~(unsigned)0 >> 1))
#define INT_MIN (-INT_MAX-1)

#define SCREENSIZE (LCD_WIDTH*LCD_HEIGHT/8) // in bytes
#define FPS 68 // default fps for headerless (old video-only) file
#define MAX_ACC 20 // maximum FF/FR speedup
#define FF_TICKS 3000; // experimentally found nice

// trigger levels, we need about 80 kB/sec
#define SPINUP_INIT 5000 // from what level on to refill, in milliseconds
#define SPINUP_SAFETY 700 // how much on top of the measured spinup time
#define CHUNK (1024*32) // read size


/****************** prototypes ******************/
void timer4_isr(void); // IMIA4 ISR
int check_button(void); // determine next relative frame


/****************** data types ******************/

// plugins don't introduce headers, so structs are repeated from rvf_format.h

#define HEADER_MAGIC 0x52564668 // "RVFh" at file start 
#define AUDIO_MAGIC  0x41756446 // "AudF" for each audio block
#define FILEVERSION  100 // 1.00

// format type definitions
#define VIDEOFORMAT_NO_VIDEO       0
#define VIDEOFORMAT_RAW            1
#define AUDIOFORMAT_NO_AUDIO       0
#define AUDIOFORMAT_MP3            1
#define AUDIOFORMAT_MP3_BITSWAPPED 2

// bit flags
#define FLAG_LOOP 0x00000001 // loop the playback, e.g. for stills

typedef struct // contains whatever might be useful to the player
{
    // general info (16 entries = 64 byte)
    unsigned long magic; // HEADER_MAGIC
    unsigned long version; // file version
    unsigned long flags; // combination of FLAG_xx
    unsigned long blocksize; // how many bytes per block (=video frame)
    unsigned long bps_average; // bits per second of the whole stream
    unsigned long bps_peak; // max. of above (audio may be VBR)
    unsigned long resume_pos; // file position to resume to
    unsigned long reserved[9]; // reserved, should be zero

    // video info (16 entries = 64 byte)
    unsigned long video_format; // one of VIDEOFORMAT_xxx
    unsigned long video_1st_frame; // byte position of first video frame
    unsigned long video_duration; // total length of video part, in ms
    unsigned long video_payload_size; // total amount of video data, in bytes
    unsigned long video_bitrate; // derived from resolution and frame time, in bps
    unsigned long video_frametime; // frame interval in 11.0592 MHz clocks
    long video_preroll; // video is how much ahead, in 11.0592 MHz clocks
    unsigned long video_width; // in pixels
    unsigned long video_height; // in pixels
    unsigned long video_reserved[7]; // reserved, should be zero

    // audio info (16 entries = 64 byte)
    unsigned long audio_format; // one of AUDIOFORMAT_xxx
    unsigned long audio_1st_frame; // byte position of first video frame
    unsigned long audio_duration; // total length of audio part, in ms
    unsigned long audio_payload_size; // total amount of audio data, in bytes
    unsigned long audio_avg_bitrate; // average audio bitrate, in bits per second
    unsigned long audio_peak_bitrate; // maximum bitrate
    unsigned long audio_headersize; // offset to payload in audio frames
    long audio_min_associated; // minimum offset to video frame, in bytes
    long audio_max_associated; // maximum offset to video frame, in bytes
    unsigned long audio_reserved[7]; // reserved, should be zero

   // more to come... ?

    // Note: padding up to 'blocksize' with zero following this header
} tFileHeader;

typedef struct // the little header for all audio blocks
{
    unsigned long magic; // AUDIO_MAGIC indicates an audio block
	unsigned char previous_block; // previous how many blocks backwards
    unsigned char next_block; // next how many blocks forward
	short associated_video; // offset to block with corresponding video
    unsigned short frame_start; // offset to first frame starting in this block
    unsigned short frame_end; // offset to behind last frame ending in this block
} tAudioFrameHeader;


/****************** globals ******************/

static struct plugin_api* rb; /* here is a global api struct pointer */
static char gPrint[32]; /* a global printf buffer, saves stack */


// playstate
static struct 
{
    enum 
    {
        paused,
        playing,
    } state;
    bool bAudioUnderrun;
    bool bVideoUnderrun;
    bool bHasAudio;
    bool bHasVideo;
    int nTimeOSD; // OSD should stay for this many frames
    bool bDirtyOSD; // OSD needs redraw
    bool bRefilling; // set if refilling buffer
    bool bSeeking;
    int nSeekAcc; // accelleration value for seek
    int nSeekPos; // current file position for seek
    bool bDiskSleep; // disk is suspended
#if FREQ == 12000000 /* Ondio speed kludge */
    int nFrameTimeAdjusted;
#endif
} gPlay;

// buffer information
static struct
{
    int bufsize;
    int granularity; // common multiple of block and sector size
    unsigned char* pBufStart; // start of ring buffer
    unsigned char* pBufEnd; // end of ring buffer
    unsigned char* pOSD; // OSD memory (112 bytes for 112*8 pixels)

    int vidcount; // how many video blocks are known in a row
    unsigned char* pBufFill; // write pointer for disk, owned by main task
    unsigned char* pReadVideo; // video readout, maintained by timer ISR
    unsigned char* pReadAudio; // audio readout, maintained by demand ISR
    bool bEOF; // flag for end of file
    int low_water; // reload threshold 
    int high_water; // end of reload threshold
    int spinup_safety; // safety margin when recalculating low_water
    int nReadChunk; // how much data for normal buffer fill
    int nSeekChunk; // how much data while seeking
} gBuf;

// statistics
static struct
{
    int minAudioAvail;
    int minVideoAvail;
    int nAudioUnderruns;
    int nVideoUnderruns;
    long minSpinup;
    long maxSpinup;
} gStats;

tFileHeader gFileHdr; // file header

/****************** implementation ******************/

// tool function: return how much playable audio/video is left
int Available(unsigned char* pSnapshot)
{
    if (pSnapshot <= gBuf.pBufFill)
        return gBuf.pBufFill - pSnapshot;
    else
        return gBuf.bufsize - (pSnapshot - gBuf.pBufFill);
}

// debug function to draw buffer indicators
void DrawBuf(void)
{
    int fill, video, audio;

    rb->memset(gBuf.pOSD, 0x10, LCD_WIDTH); // draw line
    gBuf.pOSD[0] = gBuf.pOSD[LCD_WIDTH-1] = 0xFE; // ends

    // calculate new tick positions
    fill = 1 + ((gBuf.pBufFill - gBuf.pBufStart) * (LCD_WIDTH-2)) / gBuf.bufsize;
    video = 1 + ((gBuf.pReadVideo - gBuf.pBufStart) * (LCD_WIDTH-2)) / gBuf.bufsize;
    audio = 1 + ((gBuf.pReadAudio - gBuf.pBufStart) * (LCD_WIDTH-2)) / gBuf.bufsize;

    gBuf.pOSD[fill] |= 0x20; // below the line, two pixels
    gBuf.pOSD[video] |= 0x08; // one above
    gBuf.pOSD[audio] |= 0x04; // two above

    if (gPlay.state == paused) // we have to draw ourselves
        rb->lcd_update_rect(0, LCD_HEIGHT-8, LCD_WIDTH, 8);
    else
        gPlay.bDirtyOSD = true; // redraw it with next timer IRQ
}


// helper function to draw a position indicator
void DrawPosition(int pos, int total)
{
    int w,h;
    int sec; // estimated seconds


    /* print the estimated position */   
    sec = pos / (gFileHdr.bps_average/8);
    if (sec < 100*60) /* fits into mm:ss format */
        rb->snprintf(gPrint, sizeof(gPrint), "%02d:%02dm", sec/60, sec%60);
    else /* a very long clip, hh:mm format */
        rb->snprintf(gPrint, sizeof(gPrint), "%02d:%02dh", sec/3600, (sec/60)%60);
    rb->lcd_puts(0, 7, gPrint);

    /* draw a slider over the rest of the line */
    rb->lcd_getstringsize(gPrint, &w, &h);
    w++;
    rb->scrollbar(w, LCD_HEIGHT-7, LCD_WIDTH-w, 7, total, 0, pos, HORIZONTAL);

    if (gPlay.state == paused) // we have to draw ourselves
        rb->lcd_update_rect(0, LCD_HEIGHT-8, LCD_WIDTH, 8);
    else // let the display time do it
    {
        gPlay.nTimeOSD = 70;
        gPlay.bDirtyOSD = true; // redraw it with next timer IRQ
    }
}


// helper function to change the volume by a certain amount, +/-
void ChangeVolume(int delta)
{
    int vol = rb->global_settings->volume + delta;

    if (vol > 100) vol = 100;
    else if (vol < 0) vol = 0;
    if (vol != rb->global_settings->volume)
    {
        rb->sound_set(SOUND_VOLUME, vol);
        rb->global_settings->volume = vol;
        rb->snprintf(gPrint, sizeof(gPrint), "Vol: %d", vol);
        rb->lcd_puts(0, 7, gPrint);
        if (gPlay.state == paused) // we have to draw ourselves
            rb->lcd_update_rect(0, LCD_HEIGHT-8, LCD_WIDTH, 8);
        else // let the display time do it
        {
            gPlay.nTimeOSD = 50; // display it for 50 frames
            gPlay.bDirtyOSD = true; // let the refresh copy it to LCD
        }
    }
}


// helper function to change the LCD contrast by a certain amount, +/-
void ChangeContrast(int delta)
{
    static int mycontrast = -1; /* the "permanent" value while running */
    int contrast; /* updated value */

    if (mycontrast == -1)
        mycontrast = rb->global_settings->contrast;

    contrast = mycontrast + delta;
    if (contrast > 63) contrast = 63;
    else if (contrast < 5) contrast = 5;
    if (contrast != mycontrast)
    {
        rb->lcd_set_contrast(contrast);
        mycontrast = contrast;
        rb->snprintf(gPrint, sizeof(gPrint), "Contrast: %d", contrast);
        rb->lcd_puts(0, 7, gPrint);
        if (gPlay.state == paused) // we have to draw ourselves
            rb->lcd_update_rect(0, LCD_HEIGHT-8, LCD_WIDTH, 8);
        else // let the display time do it
        {
            gPlay.nTimeOSD = 50; // display it for 50 frames
            gPlay.bDirtyOSD = true; // let the refresh copy it to LCD
        }
    }
}


// sync the video to the current audio
void SyncVideo(void)
{
    tAudioFrameHeader* pAudioBuf;

    pAudioBuf = (tAudioFrameHeader*)(gBuf.pReadAudio);
    if (pAudioBuf->magic == AUDIO_MAGIC)
    {
        gBuf.vidcount = 0; // nothing known
        // sync the video position
        gBuf.pReadVideo = gBuf.pReadAudio + 
            (long)pAudioBuf->associated_video * (long)gFileHdr.blocksize;
    
        // handle possible wrap
        if (gBuf.pReadVideo >= gBuf.pBufEnd)
            gBuf.pReadVideo -= gBuf.bufsize;
        else if (gBuf.pReadVideo < gBuf.pBufStart)
            gBuf.pReadVideo += gBuf.bufsize;
    }
}


// timer interrupt handler to display a frame
void timer4_isr(void)
{
    int available;
    tAudioFrameHeader* pAudioBuf;
    int height; // height to display

    // reduce height if we have OSD on
    height = gFileHdr.video_height/8;        
    if (gPlay.nTimeOSD > 0)
    {
        gPlay.nTimeOSD--;
        height = MIN(LCD_HEIGHT/8-1, height); // reserve bottom line
        if (gPlay.bDirtyOSD)
        {   // OSD to bottom line
            rb->lcd_blit(gBuf.pOSD, 0, LCD_HEIGHT/8-1, 
                LCD_WIDTH, 1, LCD_WIDTH);
            gPlay.bDirtyOSD = false;
        }
    }

    rb->lcd_blit(gBuf.pReadVideo, 0, 0, 
        gFileHdr.video_width, height, gFileHdr.video_width);

    available = Available(gBuf.pReadVideo);

    // loop to skip audio frame(s)
    while(1)
    {
        // just for the statistics
        if (!gBuf.bEOF && available < gStats.minVideoAvail)
            gStats.minVideoAvail = available;

        if (available <= (int)gFileHdr.blocksize)
        {   // no data for next frame

            if (gBuf.bEOF && (gFileHdr.flags & FLAG_LOOP))
            {   // loop now, assuming the looped clip fits in memory
                gBuf.pReadVideo = gBuf.pBufStart + gFileHdr.video_1st_frame;
                // FixMe: pReadVideo is incremented below
            }
            else
            {
                gPlay.bVideoUnderrun = true;
                rb->plugin_unregister_timer(); // disable ourselves
                return; // no data available
            }
        }
        else // normal advance for next time
        {
            gBuf.pReadVideo += gFileHdr.blocksize;
            if (gBuf.pReadVideo >= gBuf.pBufEnd)
                gBuf.pReadVideo -= gBuf.bufsize; // wraparound
            available -= gFileHdr.blocksize;
        }

        if (!gPlay.bHasAudio)
            break; // no need to skip any audio
        
        if (gBuf.vidcount)
        {   
            // we know the next is a video frame
            gBuf.vidcount--;
            break; // exit the loop
        }
        
        pAudioBuf = (tAudioFrameHeader*)(gBuf.pReadVideo);
        if (pAudioBuf->magic == AUDIO_MAGIC)
        {   // we ran into audio, can happen after seek
            gBuf.vidcount = pAudioBuf->next_block;
            if (gBuf.vidcount)
                gBuf.vidcount--; // minus the audio block
        }
    } // while
}


// ISR function to get more mp3 data
void GetMoreMp3(unsigned char** start, int* size)
{
    int available;
    int advance;

    tAudioFrameHeader* pAudioBuf = (tAudioFrameHeader*)(gBuf.pReadAudio);

    advance = pAudioBuf->next_block * gFileHdr.blocksize;

    available = Available(gBuf.pReadAudio);

    // just for the statistics
    if (!gBuf.bEOF && available < gStats.minAudioAvail)
        gStats.minAudioAvail = available;
    
    if (available < advance + (int)gFileHdr.blocksize || advance == 0)
    {
        gPlay.bAudioUnderrun = true;
        return; // no data available
    }

    gBuf.pReadAudio += advance;
    if (gBuf.pReadAudio >= gBuf.pBufEnd)
        gBuf.pReadAudio -= gBuf.bufsize; // wraparound

    *start = gBuf.pReadAudio + gFileHdr.audio_headersize;
    *size = gFileHdr.blocksize - gFileHdr.audio_headersize;
}


int WaitForButton(void)
{
    int button;
    
    do
    {
        button = rb->button_get(true);
        rb->default_event_handler(button);
    } while ((button & BUTTON_REL) && button != SYS_USB_CONNECTED);
    
    return button;
}


bool WantResume(int fd)
{
    int button;

    rb->lcd_puts(0, 0, "Resume to this");
    rb->lcd_puts(0, 1, "last position?");
    rb->lcd_puts(0, 2, "PLAY = yes");
    rb->lcd_puts(0, 3, "Any Other = no");
    rb->lcd_puts(0, 4, " (plays from start)");
    DrawPosition(gFileHdr.resume_pos, rb->filesize(fd));
    rb->lcd_update();

    button = WaitForButton();
    return (button == VIDEO_RESUME);
}


int SeekTo(int fd, int nPos)
{
    int read_now, got_now;

    if (gPlay.bHasAudio)
        rb->mp3_play_stop(); // stop audio ISR
    if (gPlay.bHasVideo)
        rb->plugin_unregister_timer(); // stop the timer

    rb->lseek(fd, nPos, SEEK_SET);

    gBuf.pBufFill = gBuf.pBufStart; // all empty
    gBuf.pReadVideo = gBuf.pReadAudio = gBuf.pBufStart;

    read_now = gBuf.low_water - 1; // less than low water, so loading will continue
    read_now -= read_now % gBuf.granularity; // round down to granularity
    got_now = rb->read(fd, gBuf.pBufFill, read_now);
    gBuf.bEOF = (read_now != got_now);
    gBuf.pBufFill += got_now;

    if (nPos == 0)
    {   // we seeked to the start
        if (gPlay.bHasVideo)
            gBuf.pReadVideo += gFileHdr.video_1st_frame;

        if (gPlay.bHasAudio)
            gBuf.pReadAudio += gFileHdr.audio_1st_frame;
    }
    else
    {   // we have to search for the positions
        if (gPlay.bHasAudio) // prepare audio playback, if contained
        {
            // search for audio frame
            while (((tAudioFrameHeader*)(gBuf.pReadAudio))->magic != AUDIO_MAGIC)
                gBuf.pReadAudio += gFileHdr.blocksize;
            
            if (gPlay.bHasVideo)
                SyncVideo(); // pick the right video for that
        }
    }

    // synchronous start
    gPlay.state = playing;
    if (gPlay.bHasAudio)
    {
        gPlay.bAudioUnderrun = false;
        rb->mp3_play_data(gBuf.pReadAudio + gFileHdr.audio_headersize,
                gFileHdr.blocksize - gFileHdr.audio_headersize, GetMoreMp3);
        rb->mp3_play_pause(true); // kickoff audio
    }
    if (gPlay.bHasVideo)
    {
        gPlay.bVideoUnderrun = false;
        // start display interrupt
#if FREQ == 12000000 /* Ondio speed kludge */
        rb->plugin_register_timer(gPlay.nFrameTimeAdjusted, 1, timer4_isr);
#else
        rb->plugin_register_timer(gFileHdr.video_frametime, 1, timer4_isr);
#endif
    }

    return 0;
}

// called from default_event_handler_ex() or at end of playback
void Cleanup(void *fd)
{
    rb->close(*(int*)fd); // close the file

    if (gPlay.bHasVideo)
        rb->plugin_unregister_timer(); // stop video ISR, now I can use the display again

    if (gPlay.bHasAudio)
        rb->mp3_play_stop(); // stop audio ISR

    // restore normal backlight setting
    rb->backlight_set_timeout(rb->global_settings->backlight_timeout);

    // restore normal contrast
    rb->lcd_set_contrast(rb->global_settings->contrast);
}

// returns >0 if continue, =0 to stop, <0 to abort (USB)
int PlayTick(int fd)
{
    int button;
    static int lastbutton = 0;
    int avail_audio = -1, avail_video = -1;
    int retval = 1;
    int filepos;

    // check buffer level
    
    if (gPlay.bHasAudio)
        avail_audio = Available(gBuf.pReadAudio);
    if (gPlay.bHasVideo)
        avail_video = Available(gBuf.pReadVideo);

    if ((gPlay.bHasAudio && avail_audio < gBuf.low_water)
     || (gPlay.bHasVideo && avail_video < gBuf.low_water))
    {
        gPlay.bRefilling = true; /* go to refill mode */
    }

    if ((!gPlay.bHasAudio || gPlay.bAudioUnderrun)
     && (!gPlay.bHasVideo || gPlay.bVideoUnderrun)
     && gBuf.bEOF)
    {
        if (gFileHdr.resume_pos)
        {   // we played til the end, clear resume position
            gFileHdr.resume_pos = 0;
            rb->lseek(fd, 0, SEEK_SET); // save resume position
            rb->write(fd, &gFileHdr, sizeof(gFileHdr));
        }
        Cleanup(&fd);
        return 0; // all expired
    }

    if (!gPlay.bRefilling || gBuf.bEOF)
    {   // nothing to do
        button = rb->button_get_w_tmo(HZ/10);
    }
    else
    {   // refill buffer
        int read_now, got_now;
        int buf_free;
        long spinup; // measure the spinup time
        
        // how much can we reload, don't fill completely, would appear empty
        buf_free = gBuf.bufsize - MAX(avail_audio, avail_video) - gBuf.high_water;
        if (buf_free < 0)
            buf_free = 0; // just for safety
        buf_free -= buf_free % gBuf.granularity; // round down to granularity

        // in one piece max. up to buffer end (wrap after that)
        read_now = MIN(buf_free, gBuf.pBufEnd - gBuf.pBufFill);

        // load piecewise, to stay responsive
        read_now = MIN(read_now, gBuf.nReadChunk);

        if (read_now == buf_free)
            gPlay.bRefilling = false; // last piece requested

        spinup = *rb->current_tick; // in case this is interesting below
        
        got_now = rb->read(fd, gBuf.pBufFill, read_now);
        if (got_now != read_now || read_now == 0)
        {
            gBuf.bEOF = true;
            gPlay.bRefilling = false;
        }

        if (gPlay.bDiskSleep) // statistics about the spinup time
        {
            spinup = *rb->current_tick - spinup;
            gPlay.bDiskSleep = false;
            if (spinup > gStats.maxSpinup)
                gStats.maxSpinup = spinup;
            if (spinup < gStats.minSpinup)
                gStats.minSpinup = spinup;

            // recalculate the low water mark from real measurements
            gBuf.low_water = (gStats.maxSpinup + gBuf.spinup_safety) 
                             * gFileHdr.bps_peak / 8 / HZ;
        }

        if (!gPlay.bRefilling 
            && rb->global_settings->disk_spindown < 20) // condition for test only
        {
            rb->ata_sleep(); // no point in leaving the disk run til timeout
            gPlay.bDiskSleep = true;
        }

        gBuf.pBufFill += got_now;
        if (gBuf.pBufFill >= gBuf.pBufEnd)
            gBuf.pBufFill = gBuf.pBufStart; // wrap

        rb->yield(); // have mercy with the other threads
        button = rb->button_get(false);
    }

    // check keypresses

    if (button != BUTTON_NONE)
    {
        filepos = rb->lseek(fd, 0, SEEK_CUR);

        if (gPlay.bHasVideo) // video position is more accurate
            filepos -= Available(gBuf.pReadVideo); // take video position
        else
            filepos -= Available(gBuf.pReadAudio); // else audio
            
        switch (button)
        {   // set exit conditions
        case BUTTON_OFF:
            if (gFileHdr.magic == HEADER_MAGIC // only if file has header
                && !(gFileHdr.flags & FLAG_LOOP)) // not for stills
            {
                gFileHdr.resume_pos = filepos;
                rb->lseek(fd, 0, SEEK_SET); // save resume position
                rb->write(fd, &gFileHdr, sizeof(gFileHdr));
            }
            Cleanup(&fd);
            retval = 0; // signal "stopped" to caller
            break;
        case VIDEO_STOP_SEEK:
#ifdef VIDEO_STOP_SEEK_PRE
            if (lastbutton != VIDEO_STOP_SEEK_PRE)
                break;
#endif
            if (gPlay.bSeeking)
            {
                gPlay.bSeeking = false;
                gPlay.state = playing;
                SeekTo(fd, gPlay.nSeekPos);
            }
            else if (gPlay.state == playing)
            {
                gPlay.state = paused;
                if (gPlay.bHasAudio)
                    rb->mp3_play_pause(false); // pause audio
                if (gPlay.bHasVideo)
                    rb->plugin_unregister_timer(); // stop the timer
            }
            else if (gPlay.state == paused)
            {
                gPlay.state = playing;
                if (gPlay.bHasAudio)
                {
                    if (gPlay.bHasVideo)
                        SyncVideo();
                    rb->mp3_play_pause(true); // play audio
                }
                if (gPlay.bHasVideo)
                {   // start the video
#if FREQ == 12000000 /* Ondio speed kludge */
                    rb->plugin_register_timer(
                        gPlay.nFrameTimeAdjusted, 1, timer4_isr);
#else
                    rb->plugin_register_timer(
                        gFileHdr.video_frametime, 1, timer4_isr);
#endif
                }
            }
            break;
        case BUTTON_UP:
        case BUTTON_UP | BUTTON_REPEAT:
            if (gPlay.bHasAudio)
                ChangeVolume(1);
            break;
        case BUTTON_DOWN:
        case BUTTON_DOWN | BUTTON_REPEAT:
            if (gPlay.bHasAudio)
                ChangeVolume(-1);
            break;
        case BUTTON_LEFT:
        case BUTTON_LEFT | BUTTON_REPEAT:
            if (!gPlay.bSeeking) // prepare seek
            {
                gPlay.nSeekPos = filepos;
                gPlay.bSeeking = true;
                gPlay.nSeekAcc = 0;
            }
            else if (gPlay.nSeekAcc > 0) // other direction, stop sliding
                gPlay.nSeekAcc = 0;
            else
                gPlay.nSeekAcc--;
            break;
        case BUTTON_RIGHT:
        case BUTTON_RIGHT | BUTTON_REPEAT:
            if (!gPlay.bSeeking) // prepare seek
            {
                gPlay.nSeekPos = filepos;
                gPlay.bSeeking = true;
                gPlay.nSeekAcc = 0;
            }
            else if (gPlay.nSeekAcc < 0) // other direction, stop sliding
                gPlay.nSeekAcc = 0;
            else
                gPlay.nSeekAcc++;
            break;
#ifdef VIDEO_DEBUG
        case VIDEO_DEBUG: // debug key
        case VIDEO_DEBUG | BUTTON_REPEAT:
            DrawBuf(); // show buffer status
            gPlay.nTimeOSD = 30;
            gPlay.bDirtyOSD = true;
            break;
#endif
        case VIDEO_CONTRAST_DOWN: // contrast down
        case VIDEO_CONTRAST_DOWN | BUTTON_REPEAT:
            if (gPlay.bHasVideo)
                ChangeContrast(-1);
            break;
        case VIDEO_CONTRAST_UP: // contrast up
        case VIDEO_CONTRAST_UP | BUTTON_REPEAT:
            if (gPlay.bHasVideo)
                ChangeContrast(1);
            break;
        default:
            if (rb->default_event_handler_ex(button, Cleanup, &fd)
                == SYS_USB_CONNECTED)
                retval = -1; // signal "aborted" to caller
            break;
        }

        lastbutton = button;
    } /*  if (button != BUTTON_NONE) */

    
    // handle seeking
    
    if (gPlay.bSeeking) // seeking?
    {
        if (gPlay.nSeekAcc < -MAX_ACC)
            gPlay.nSeekAcc = -MAX_ACC;
        else if (gPlay.nSeekAcc > MAX_ACC)
            gPlay.nSeekAcc = MAX_ACC;
        
        gPlay.nSeekPos += gPlay.nSeekAcc * gBuf.nSeekChunk;
        if (gPlay.nSeekPos < 0)
            gPlay.nSeekPos = 0;
        if (gPlay.nSeekPos > rb->filesize(fd) - gBuf.granularity)
        {
            gPlay.nSeekPos = rb->filesize(fd);
            gPlay.nSeekPos -= gPlay.nSeekPos % gBuf.granularity;
        }
        DrawPosition(gPlay.nSeekPos, rb->filesize(fd));
    }


    // check + recover underruns
    
    if ((gPlay.bAudioUnderrun || gPlay.bVideoUnderrun) && !gBuf.bEOF)
    {
        gBuf.spinup_safety += HZ/2; // add extra spinup time for the future
        filepos = rb->lseek(fd, 0, SEEK_CUR);

        if (gPlay.bHasVideo && gPlay.bVideoUnderrun)
        {
            gStats.nVideoUnderruns++;
            filepos -= Available(gBuf.pReadVideo); // take video position
            SeekTo(fd, filepos);
        }
        else if (gPlay.bHasAudio && gPlay.bAudioUnderrun)
        {
            gStats.nAudioUnderruns++;
            filepos -= Available(gBuf.pReadAudio); // else audio
            SeekTo(fd, filepos);
        }
    }

    return retval;
}


int main(char* filename)
{
    int file_size;
    int fd; /* file descriptor handle */
    int read_now, got_now;
    int button = 0;
    int retval;

    // try to open the file
    fd = rb->open(filename, O_RDWR);
    if (fd < 0)
        return PLUGIN_ERROR;
    file_size =  rb->filesize(fd);

    // init statistics
    rb->memset(&gStats, 0, sizeof(gStats));
    gStats.minAudioAvail = gStats.minVideoAvail = INT_MAX;
    gStats.minSpinup = INT_MAX;

    // init playback state
    rb->memset(&gPlay, 0, sizeof(gPlay));

    // init buffer
    rb->memset(&gBuf, 0, sizeof(gBuf));
    gBuf.pOSD = rb->lcd_framebuffer + LCD_WIDTH*7; // last screen line
    gBuf.pBufStart = rb->plugin_get_audio_buffer(&gBuf.bufsize);
    //gBuf.bufsize = 1700*1024; // test, like 2MB version!!!!
    gBuf.pBufFill = gBuf.pBufStart; // all empty

    // load file header
    read_now = sizeof(gFileHdr);
    got_now = rb->read(fd, &gFileHdr, read_now);
    rb->lseek(fd, 0, SEEK_SET); // rewind to restart sector-aligned
    if (got_now != read_now)
    {
        rb->close(fd);
        return (PLUGIN_ERROR);
    }

    // check header
    if (gFileHdr.magic != HEADER_MAGIC)
    {   // old file, use default info
        rb->memset(&gFileHdr, 0, sizeof(gFileHdr));
        gFileHdr.blocksize = SCREENSIZE;
        if (file_size < SCREENSIZE * FPS) // less than a second
            gFileHdr.flags |= FLAG_LOOP;
        gFileHdr.video_format = VIDEOFORMAT_RAW;
        gFileHdr.video_width = LCD_WIDTH;
        gFileHdr.video_height = LCD_HEIGHT;
        gFileHdr.video_frametime = 11059200 / FPS;
        gFileHdr.bps_peak = gFileHdr.bps_average = LCD_WIDTH * LCD_HEIGHT * FPS;
    }

#if FREQ == 12000000 /* Ondio speed kludge, 625 / 576 == 12000000 / 11059200 */
    gPlay.nFrameTimeAdjusted = (gFileHdr.video_frametime * 625) / 576;
#endif

    // continue buffer init: align the end, calc low water, read sizes
    gBuf.granularity = gFileHdr.blocksize;
    while (gBuf.granularity % 512) // common multiple of sector size
        gBuf.granularity *= 2;
    gBuf.bufsize -= gBuf.bufsize % gBuf.granularity; // round down
    gBuf.pBufEnd = gBuf.pBufStart + gBuf.bufsize;
    gBuf.low_water = SPINUP_INIT * gFileHdr.bps_peak / 8000;
    gBuf.spinup_safety = SPINUP_SAFETY * HZ / 1000; // in time ticks
    if (gFileHdr.audio_min_associated < 0)
        gBuf.high_water = 0 - gFileHdr.audio_min_associated;
    else
        gBuf.high_water = 1; // never fill buffer completely, would appear empty
    gBuf.nReadChunk = (CHUNK + gBuf.granularity - 1); // round up
    gBuf.nReadChunk -= gBuf.nReadChunk % gBuf.granularity;// and align
    gBuf.nSeekChunk = rb->filesize(fd) / FF_TICKS;
    gBuf.nSeekChunk += gBuf.granularity - 1; // round up
    gBuf.nSeekChunk -= gBuf.nSeekChunk % gBuf.granularity; // and align

    // prepare video playback, if contained
    if (gFileHdr.video_format == VIDEOFORMAT_RAW)
    {
        gPlay.bHasVideo = true;
        if (rb->global_settings->backlight_timeout > 0)
            rb->backlight_set_timeout(1); // keep the light on
    }

    // prepare audio playback, if contained
    if (gFileHdr.audio_format == AUDIOFORMAT_MP3_BITSWAPPED)
    {
        gPlay.bHasAudio = true;
    }

    // start playback by seeking to zero or resume position
    if (gFileHdr.resume_pos && WantResume(fd)) // ask the user
        SeekTo(fd, gFileHdr.resume_pos);
    else
        SeekTo(fd, 0);

    // all that's left to do is keep the buffer full
    do // the main loop
    {
        retval = PlayTick(fd);
    } while (retval > 0);

    if (retval < 0) // aborted?
    {
        return PLUGIN_USB_CONNECTED;
    }

#ifndef DEBUG // for release compilations, only display the stats in case of error
    if (gStats.nAudioUnderruns || gStats.nVideoUnderruns)
#endif
    {
        // display statistics
        rb->lcd_clear_display();
        rb->snprintf(gPrint, sizeof(gPrint), "%d Audio Underruns", gStats.nAudioUnderruns);
        rb->lcd_puts(0, 0, gPrint);
        rb->snprintf(gPrint, sizeof(gPrint), "%d Video Underruns", gStats.nVideoUnderruns);
        rb->lcd_puts(0, 1, gPrint);
        rb->snprintf(gPrint, sizeof(gPrint), "%d MinAudio bytes", gStats.minAudioAvail);
        rb->lcd_puts(0, 2, gPrint);
        rb->snprintf(gPrint, sizeof(gPrint), "%d MinVideo bytes", gStats.minVideoAvail);
        rb->lcd_puts(0, 3, gPrint);
        rb->snprintf(gPrint, sizeof(gPrint), "MinSpinup %d.%02d", gStats.minSpinup/HZ, gStats.minSpinup%HZ);
        rb->lcd_puts(0, 4, gPrint);