hvirtual/quicktime/quicktime.c

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#include "colormodels.h"
#include "funcprotos.h"
#include "interlacemodes.h"
#include "quicktime.h"
#include <string.h>
#include <sys/stat.h>
#include "workarounds.h"

int quicktime_make_streamable(char *in_path, char *out_path)
{
        quicktime_t file, *old_file, new_file;
        int moov_exists = 0, mdat_exists = 0, result, atoms = 1;
        int64_t mdat_start, mdat_size;
        quicktime_atom_t leaf_atom;
        int64_t moov_length;
        
        quicktime_init(&file);

/* find the moov atom in the old file */
        
        if(!(file.stream = fopen(in_path, "rb")))
        {
                perror("quicktime_make_streamable");
                return 1;
        }

        file.total_length = quicktime_get_file_length(in_path);

/* get the locations of moov and mdat atoms */
        do
        {
/*printf("%x\n", quicktime_position(&file)); */
                result = quicktime_atom_read_header(&file, &leaf_atom);

                if(!result)
                {
                        if(quicktime_atom_is(&leaf_atom, "moov"))
                        {
                                moov_exists = atoms;
                                moov_length = leaf_atom.size;
                        }
                        else
                        if(quicktime_atom_is(&leaf_atom, "mdat"))
                        {
                                mdat_start = quicktime_position(&file) - HEADER_LENGTH;
                                mdat_size = leaf_atom.size;
                                mdat_exists = atoms;
                        }

                        quicktime_atom_skip(&file, &leaf_atom);

                        atoms++;
                }
        }while(!result && quicktime_position(&file) < file.total_length);

        fclose(file.stream);

        if(!moov_exists)
        {
                printf("quicktime_make_streamable: no moov atom\n");
                return 1;
        }

        if(!mdat_exists)
        {
                printf("quicktime_make_streamable: no mdat atom\n");
                return 1;
        }

/* copy the old file to the new file */
        if(moov_exists && mdat_exists)
        {
/* moov wasn't the first atom */
                if(moov_exists > 1)
                {
                        char *buffer;
                        int64_t buf_size = 1000000;

                        result = 0;

/* read the header proper */
                        if(!(old_file = quicktime_open(in_path, 1, 0)))
                        {
                                return 1;
                        }

                        quicktime_shift_offsets(&(old_file->moov), moov_length);

/* open the output file */
                        if(!(new_file.stream = fopen(out_path, "wb")))
                        {
                                perror("quicktime_make_streamable");
                                result =  1;
                        }
                        else
                        {
/* set up some flags */
                                new_file.wr = 1;
                                new_file.rd = 0;
                                quicktime_write_moov(&new_file, &(old_file->moov));
                                quicktime_set_position(old_file, mdat_start);

                                if(!(buffer = calloc(1, buf_size)))
                                {
                                        result = 1;
                                        printf("quicktime_make_streamable: out of memory\n");
                                }
                                else
                                {
                                        while(quicktime_position(old_file) < mdat_start + mdat_size && !result)
                                        {
                                                if(quicktime_position(old_file) + buf_size > mdat_start + mdat_size)
                                                        buf_size = mdat_start + mdat_size - quicktime_position(old_file);

                                                if(!quicktime_read_data(old_file, buffer, buf_size)) result = 1;
                                                if(!result)
                                                {
                                                        if(!quicktime_write_data(&new_file, buffer, buf_size)) result = 1;
                                                }
                                        }
                                        free(buffer);
                                }
                                fclose(new_file.stream);
                        }
                        quicktime_close(old_file);
                }
                else
                {
                        printf("quicktime_make_streamable: header already at 0 offset\n");
                        return 0;
                }
        }
        
        return 0;
}



void quicktime_set_copyright(quicktime_t *file, char *string)
{
        quicktime_set_udta_string(&(file->moov.udta.copyright), &(file->moov.udta.copyright_len), string);
}

void quicktime_set_name(quicktime_t *file, char *string)
{
        quicktime_set_udta_string(&(file->moov.udta.name), &(file->moov.udta.name_len), string);
}

void quicktime_set_info(quicktime_t *file, char *string)
{
        quicktime_set_udta_string(&(file->moov.udta.info), &(file->moov.udta.info_len), string);
}

char* quicktime_get_copyright(quicktime_t *file)
{
        return file->moov.udta.copyright;
}

char* quicktime_get_name(quicktime_t *file)
{
        return file->moov.udta.name;
}

char* quicktime_get_info(quicktime_t *file)
{
        return file->moov.udta.info;
}


int quicktime_video_tracks(quicktime_t *file)
{
        int i, result = 0;
        for(i = 0; i < file->moov.total_tracks; i++)
        {
                if(file->moov.trak[i]->mdia.minf.is_video) result++;
        }
        return result;
}

int quicktime_audio_tracks(quicktime_t *file)
{
        int i, result = 0;
        quicktime_minf_t *minf;
        for(i = 0; i < file->moov.total_tracks; i++)
        {
                minf = &(file->moov.trak[i]->mdia.minf);
                if(minf->is_audio)
                        result++;
        }
        return result;
}

int quicktime_set_audio(quicktime_t *file, 
                                                int channels,
                                                long sample_rate,
                                                int bits,
                                                char *compressor)
{
        quicktime_trak_t *trak;

/* allocate an arbitrary number of tracks */
        if(channels)
        {
/* Fake the bits parameter for some formats. */
                if(quicktime_match_32(compressor, QUICKTIME_ULAW) ||
                        quicktime_match_32(compressor, QUICKTIME_IMA4)) bits = 16;

                file->atracks = (quicktime_audio_map_t*)calloc(1, sizeof(quicktime_audio_map_t));
                trak = quicktime_add_track(file);
                quicktime_trak_init_audio(file, 
                        trak, 
                        channels, 
                        sample_rate, 
                        bits, 
                        compressor);
                quicktime_init_audio_map(&(file->atracks[0]), trak);
                file->atracks[file->total_atracks].track = trak;
                file->atracks[file->total_atracks].channels = channels;
                file->atracks[file->total_atracks].current_position = 0;
                file->atracks[file->total_atracks].current_chunk = 1;
                file->total_atracks++;
        }
        return 1;   /* Return the number of tracks created */
}

int quicktime_set_video(quicktime_t *file, 
                                                int tracks, 
                                                int frame_w, 
                                                int frame_h,
                                                double frame_rate,
                                                char *compressor)
{
        int i;
        quicktime_trak_t *trak;

        if(tracks)
        {
                quicktime_mhvd_init_video(file, &(file->moov.mvhd), frame_rate);
                file->total_vtracks = tracks;
                file->vtracks = (quicktime_video_map_t*)calloc(1, sizeof(quicktime_video_map_t) * file->total_vtracks);
                for(i = 0; i < tracks; i++)
                {
                        trak = quicktime_add_track(file);
                        quicktime_trak_init_video(file, trak, frame_w, frame_h, frame_rate, compressor);
                        quicktime_init_video_map(&(file->vtracks[i]), trak);
                }
        }

        return 0;
}

void quicktime_set_framerate(quicktime_t *file, double framerate)
{
        int i;
        int new_time_scale, new_sample_duration;

        if(!file->wr)
        {
                fprintf(stderr, "quicktime_set_framerate shouldn't be called in read mode.\n");
                return;
        }

        new_time_scale = quicktime_get_timescale(framerate);
        new_sample_duration = (int)((double)new_time_scale / framerate + 0.5);

        for(i = 0; i < file->total_vtracks; i++)
        {
                file->vtracks[i].track->mdia.mdhd.time_scale = new_time_scale;
                file->vtracks[i].track->mdia.minf.stbl.stts.table[0].sample_duration = new_sample_duration;
        }
}


// Used by quicktime_set_video when creating a new file
quicktime_trak_t* quicktime_add_track(quicktime_t *file)
{
        quicktime_moov_t *moov = &(file->moov);
        quicktime_trak_t *trak;
        int i;

        for(i = moov->total_tracks; i > 0; i--)
                moov->trak[i] = moov->trak[i - 1];

        trak = 
                moov->trak[0] = 
                calloc(1, sizeof(quicktime_trak_t));
        quicktime_trak_init(trak);
        moov->total_tracks++;

        for(i = 0; i < moov->total_tracks; i++)
                moov->trak[i]->tkhd.track_id = i + 1;
        moov->mvhd.next_track_id++;
        return trak;
}

/* ============================= Initialization functions */

int quicktime_init(quicktime_t *file)
{
        bzero(file, sizeof(quicktime_t));
        quicktime_moov_init(&(file->moov));
        file->cpus = 1;
        file->color_model = BC_RGB888;
        file->current_frame = 0;
        file->is_odml = 0;
        return 0;
}

int quicktime_delete(quicktime_t *file)
{
        int i;
        if(file->total_atracks) 
        {
                for(i = 0; i < file->total_atracks; i++)
                        quicktime_delete_audio_map(&(file->atracks[i]));
                free(file->atracks);
        }

        if(file->total_vtracks)
        {
                for(i = 0; i < file->total_vtracks; i++)
                        quicktime_delete_video_map(&(file->vtracks[i]));
                free(file->vtracks);
        }

        file->total_atracks = 0;
        file->total_vtracks = 0;

        if(file->moov_data)
                free(file->moov_data);

        if(file->preload_size)
        {
                free(file->preload_buffer);
                file->preload_size = 0;
        }

        if(file->presave_buffer)
        {
                free(file->presave_buffer);
        }

        for(i = 0; i < file->total_riffs; i++)
        {
                quicktime_delete_riff(file, file->riff[i]);
        }

        quicktime_moov_delete(&(file->moov));
        quicktime_mdat_delete(&(file->mdat));
        return 0;
}

/* =============================== Optimization functions */

int quicktime_set_cpus(quicktime_t *file, int cpus)
{
        if(cpus > 0) file->cpus = cpus;
        return 0;
}

void quicktime_set_preload(quicktime_t *file, int64_t preload)
{
        file->preload_size = preload;
        if(file->preload_buffer) free(file->preload_buffer);
        file->preload_buffer = 0;
        if(preload)
                file->preload_buffer = calloc(1, preload);
        file->preload_start = 0;
        file->preload_end = 0;
        file->preload_ptr = 0;
}


int quicktime_get_timescale(double frame_rate)
{
        int timescale = 600;
/* Encode the 29.97, 23.976, 59.94 framerates */
        if(frame_rate - (int)frame_rate != 0) 
                timescale = (int)(frame_rate * 1001 + 0.5);
        else
        if((600 / frame_rate) - (int)(600 / frame_rate) != 0) 
                        timescale = (int)(frame_rate * 100 + 0.5);
//printf("quicktime_get_timescale %f %d\n", 600 / frame_rate, (int)(600 / frame_rate));
        return timescale;
}

int quicktime_seek_end(quicktime_t *file)
{
        quicktime_set_position(file, file->mdat.atom.size + file->mdat.atom.start + HEADER_LENGTH * 2);
/*printf("quicktime_seek_end %ld\n", file->mdat.atom.size + file->mdat.atom.start); */
        quicktime_update_positions(file);
        return 0;
}

int quicktime_seek_start(quicktime_t *file)
{
        quicktime_set_position(file, file->mdat.atom.start + HEADER_LENGTH * 2);
        quicktime_update_positions(file);
        return 0;
}

long quicktime_audio_length(quicktime_t *file, int track)
{
        if(file->total_atracks > 0) 
                return quicktime_track_samples(file, file->atracks[track].track);

        return 0;
}

long quicktime_video_length(quicktime_t *file, int track)
{
/*printf("quicktime_video_length %d %d\n", quicktime_track_samples(file, file->vtracks[track].track), track); */
        if(file->total_vtracks > 0)
                return quicktime_track_samples(file, file->vtracks[track].track);
        return 0;
}

long quicktime_audio_position(quicktime_t *file, int track)
{
        return file->atracks[track].current_position;
}

long quicktime_video_position(quicktime_t *file, int track)
{
        return file->vtracks[track].current_position;
}

int quicktime_update_positions(quicktime_t *file)
{
/* Get the sample position from the file offset */
/* for routines that change the positions of all tracks, like */
/* seek_end and seek_start but not for routines that reposition one track, like */
/* set_audio_position. */

        int64_t mdat_offset = quicktime_position(file) - file->mdat.atom.start;
        int64_t sample, chunk, chunk_offset;
        int i;

        if(file->total_atracks)
        {
                sample = quicktime_offset_to_sample(file->atracks[0].track, mdat_offset);
                chunk = quicktime_offset_to_chunk(&chunk_offset, file->atracks[0].track, mdat_offset);
                for(i = 0; i < file->total_atracks; i++)
                {
                        file->atracks[i].current_position = sample;
                        file->atracks[i].current_chunk = chunk;
                }
        }

        if(file->total_vtracks)
        {
                sample = quicktime_offset_to_sample(file->vtracks[0].track, mdat_offset);
                chunk = quicktime_offset_to_chunk(&chunk_offset, file->vtracks[0].track, mdat_offset);
                for(i = 0; i < file->total_vtracks; i++)
                {
                        file->vtracks[i].current_position = sample;
                        file->vtracks[i].current_chunk = chunk;
                }
        }
        return 0;
}

int quicktime_set_audio_position(quicktime_t *file, int64_t sample, int track)
{
        int64_t offset, chunk_sample, chunk;
        quicktime_trak_t *trak;

        if(track < file->total_atracks)
        {
                trak = file->atracks[track].track;
                file->atracks[track].current_position = sample;
                quicktime_chunk_of_sample(&chunk_sample, &chunk, trak, sample);
                file->atracks[track].current_chunk = chunk;
                offset = quicktime_sample_to_offset(file, trak, sample);
                quicktime_set_position(file, offset);
        }
        else
                fprintf(stderr, "quicktime_set_audio_position: track >= file->total_atracks\n");

        return 0;
}

int quicktime_set_video_position(quicktime_t *file, int64_t frame, int track)
{
        int64_t offset, chunk_sample, chunk;
        quicktime_trak_t *trak;
        if(track >= file->total_vtracks)
        {
                fprintf(stderr, 
                        "quicktime_set_video_position: frame=%lld track=%d >= file->total_vtracks %d\n", 
                        frame,
                        track,
                        file->total_vtracks);
                track = file->total_vtracks - 1;
        }

        if(track < file->total_vtracks && track >= 0)
        {
                trak = file->vtracks[track].track;
                file->vtracks[track].current_position = frame;
                quicktime_chunk_of_sample(&chunk_sample, &chunk, trak, frame);
                file->vtracks[track].current_chunk = chunk;
                offset = quicktime_sample_to_offset(file, trak, frame);
                quicktime_set_position(file, offset);
        }
        return 0;
}

int quicktime_has_audio(quicktime_t *file)
{
        if(quicktime_audio_tracks(file)) return 1;
        return 0;
}

long quicktime_sample_rate(quicktime_t *file, int track)
{
        if(file->total_atracks)
        {
                quicktime_trak_t *trak = file->atracks[track].track;
                return trak->mdia.minf.stbl.stsd.table[0].sample_rate;
        }
        return 0;
}

int quicktime_audio_bits(quicktime_t *file, int track)
{
        if(file->total_atracks)
                return file->atracks[track].track->mdia.minf.stbl.stsd.table[0].sample_size;

        return 0;
}

char* quicktime_audio_compressor(quicktime_t *file, int track)
{
        return file->atracks[track].track->mdia.minf.stbl.stsd.table[0].format;
}

int quicktime_track_channels(quicktime_t *file, int track)
{
        if(track < file->total_atracks)
                return file->atracks[track].channels;

        return 0;
}

/* Input is absolute channel number in stream, output is quicktime_track in which the channel resides and quicktime_channel relative to the track */

int quicktime_channel_location(quicktime_t *file, int *quicktime_track, int *quicktime_channel, int channel)
{
        int current_channel = 0, current_track = 0;
        *quicktime_channel = 0;
        *quicktime_track = 0;
        for(current_channel = 0, current_track = 0; current_track < file->total_atracks; )
        {
                if(channel >= current_channel)
                {
                        *quicktime_channel = channel - current_channel;
                        *quicktime_track = current_track;
                }

                current_channel += file->atracks[current_track].channels;
                current_track++;
        }
        return 0;
}

int quicktime_has_video(quicktime_t *file)
{
        if(quicktime_video_tracks(file)) return 1;
        return 0;
}

int quicktime_video_width(quicktime_t *file, int track)
{
        if(file->total_vtracks)
                return file->vtracks[track].track->tkhd.track_width;
        return 0;
}

int quicktime_video_height(quicktime_t *file, int track)
{
        if(file->total_vtracks)
                return file->vtracks[track].track->tkhd.track_height;
        return 0;
}

int quicktime_video_depth(quicktime_t *file, int track)
{
        if(file->total_vtracks)
                return file->vtracks[track].track->mdia.minf.stbl.stsd.table[0].depth;
        return 0;
}

int quicktime_video_interlacemode(quicktime_t *file, int track)
{
        if(file->total_vtracks) {
                if (file->vtracks[track].track->mdia.minf.stbl.stsd.table[0].fields == 1)
                        return BC_ILACE_MODE_NOTINTERLACED;
                if (file->vtracks[track].track->mdia.minf.stbl.stsd.table[0].fields == 2)
                {
                        switch (file->vtracks[track].track->mdia.minf.stbl.stsd.table[0].field_dominance) 
                        {
                        case 0:
                                return BC_ILACE_MODE_UNDETECTED;
                        case 1:
                                return BC_ILACE_MODE_TOP_FIRST;
                        case 6:
                                return BC_ILACE_MODE_BOTTOM_FIRST;
                        }
                }
        }
        return BC_ILACE_MODE_UNDETECTED;
}

void quicktime_set_cmodel(quicktime_t *file, int colormodel)
{
        file->color_model = colormodel;
}

void quicktime_set_row_span(quicktime_t *file, int row_span)
{
        file->row_span = row_span;
}

void quicktime_set_window(quicktime_t *file,
        int in_x,                    /* Location of input frame to take picture */
        int in_y,
        int in_w,
        int in_h,
        int out_w,                   /* Dimensions of output frame */
        int out_h)
{
        if(in_x >= 0 && in_y >= 0 && in_w > 0 && in_h > 0 && out_w > 0 && out_h > 0)
        {
                file->do_scaling = 1;
                file->in_x = in_x;
                file->in_y = in_y;
                file->in_w = in_w;
                file->in_h = in_h;
                file->out_w = out_w;
                file->out_h = out_h;
        }
        else
        {
                file->do_scaling = 0;
/* quicktime_decode_video now sets the window for every frame based on the */
/* track dimensions */
        }
}

void quicktime_set_depth(quicktime_t *file, int depth, int track)
{
        int i;

        for(i = 0; i < file->total_vtracks; i++)
        {
                file->vtracks[i].track->mdia.minf.stbl.stsd.table[0].depth = depth;
        }
}

double quicktime_frame_rate(quicktime_t *file, int track)
{
        if(file->total_vtracks > track)
        {
                quicktime_trak_t *trak = file->vtracks[track].track;
                int time_scale = file->vtracks[track].track->mdia.mdhd.time_scale;
                int sample_duration = quicktime_sample_duration(trak);
                return (double)time_scale / sample_duration;
//              return (float)file->vtracks[track].track->mdia.mdhd.time_scale / 
//                      file->vtracks[track].track->mdia.minf.stbl.stts.table[0].sample_duration;
        }
        return 0;
}

int quicktime_frame_rate_n(quicktime_t *file, int track)
{
        if(file->total_vtracks > track)
                return file->vtracks[track].track->mdia.mdhd.time_scale;
        return 0;
}

int quicktime_frame_rate_d(quicktime_t *file, int track)
{
        if(file->total_vtracks > track)
                return file->vtracks[track].track->mdia.minf.stbl.stts.table[0].sample_duration;
        return 0;
}

char* quicktime_video_compressor(quicktime_t *file, int track)
{
        return file->vtracks[track].track->mdia.minf.stbl.stsd.table[0].format;
}

int quicktime_write_audio(quicktime_t *file, 
        char *audio_buffer, 
        long samples, 
        int track)
{
        int result;
        int64_t bytes;
        quicktime_atom_t chunk_atom;
        quicktime_audio_map_t *track_map = &file->atracks[track];
        quicktime_trak_t *trak = track_map->track;

/* write chunk for 1 track */
        bytes = samples * quicktime_audio_bits(file, track) / 8 * file->atracks[track].channels;
        quicktime_write_chunk_header(file, trak, &chunk_atom);
        result = !quicktime_write_data(file, audio_buffer, bytes);
        quicktime_write_chunk_footer(file, 
                                        trak,
                                        track_map->current_chunk,
                                        &chunk_atom, 
                                        samples);

/*      file->atracks[track].current_position += samples; */
        file->atracks[track].current_chunk++;
        return result;
}

int quicktime_write_frame(quicktime_t *file, 
        unsigned char *video_buffer, 
        int64_t bytes, 
        int track)
{
        int64_t offset = quicktime_position(file);
        int result = 0;
        quicktime_atom_t chunk_atom;
        quicktime_video_map_t *vtrack = &file->vtracks[track];
        quicktime_trak_t *trak = vtrack->track;

        quicktime_write_chunk_header(file, trak, &chunk_atom);
        result = !quicktime_write_data(file, video_buffer, bytes);
        quicktime_write_chunk_footer(file, 
                                        trak,
                                        vtrack->current_chunk,
                                        &chunk_atom, 
                                        1);
        file->vtracks[track].current_position++;
        file->vtracks[track].current_chunk++;
        return result;
}


long quicktime_read_audio(quicktime_t *file, 
        char *audio_buffer, 
        long samples, 
        int track)
{
        int64_t chunk_sample, chunk;
        int result = 0, track_num;
        quicktime_trak_t *trak = file->atracks[track].track;
        int64_t fragment_len, chunk_end;
        int64_t start_position = file->atracks[track].current_position;
        int64_t position = file->atracks[track].current_position;
        int64_t start = position, end = position + samples;
        int64_t bytes, total_bytes = 0;
        int64_t buffer_offset;

//printf("quicktime_read_audio 1\n");
        quicktime_chunk_of_sample(&chunk_sample, &chunk, trak, position);
        buffer_offset = 0;

        while(position < end && !result)
        {
                quicktime_set_audio_position(file, position, track);
                fragment_len = quicktime_chunk_samples(trak, chunk);
                chunk_end = chunk_sample + fragment_len;
                fragment_len -= position - chunk_sample;
                if(position + fragment_len > chunk_end) fragment_len = chunk_end - position;
                if(position + fragment_len > end) fragment_len = end - position;

                bytes = quicktime_samples_to_bytes(trak, fragment_len);
/*
 * printf("quicktime_read_audio 2 %llx %llx %d\n", 
 * quicktime_position(file), 
 * quicktime_position(file) + bytes, 
 * samples);
 * sleep(1);
 */
                result = !quicktime_read_data(file, &audio_buffer[buffer_offset], bytes);
//printf("quicktime_read_audio 4\n");

                total_bytes += bytes;
                position += fragment_len;
                chunk_sample = position;
                buffer_offset += bytes;
                chunk++;
        }
//printf("quicktime_read_audio 5\n");

// Create illusion of track being advanced only by samples
        file->atracks[track].current_position = start_position + samples;
        if(result) return 0;
        return total_bytes;
}

int quicktime_read_chunk(quicktime_t *file, char *output, int track, int64_t chunk, int64_t byte_start, int64_t byte_len)
{
        quicktime_set_position(file, 
                quicktime_chunk_to_offset(file, file->atracks[track].track, chunk) + 
                byte_start);
        if(quicktime_read_data(file, output, byte_len)) return 0;
        else
        return 1;
}

long quicktime_frame_size(quicktime_t *file, long frame, int track)
{
        long bytes = 0;
        quicktime_trak_t *trak = file->vtracks[track].track;

        if(trak->mdia.minf.stbl.stsz.sample_size)
        {
                bytes = trak->mdia.minf.stbl.stsz.sample_size;
        }
        else
        {
                long total_frames = quicktime_track_samples(file, trak);
                if(frame < 0) frame = 0;
                else
                if(frame > total_frames - 1) frame = total_frames - 1;
                bytes = trak->mdia.minf.stbl.stsz.table[frame].size;
        }


        return bytes;
}


long quicktime_read_frame(quicktime_t *file, unsigned char *video_buffer, int track)
{
        int64_t bytes;
        int result = 0;

        quicktime_trak_t *trak = file->vtracks[track].track;
        bytes = quicktime_frame_size(file, file->vtracks[track].current_position, track);

        quicktime_set_video_position(file, file->vtracks[track].current_position, track);
        result = quicktime_read_data(file, video_buffer, bytes);
        file->vtracks[track].current_position++;

        if(!result) return 0;
        return bytes;
}

int64_t quicktime_get_keyframe_before(quicktime_t *file, int64_t frame, int track)
{
        quicktime_trak_t *trak = file->vtracks[track].track;
        quicktime_stss_t *stss = &trak->mdia.minf.stbl.stss;
        int i;





// Offset 1
        frame++;


        for(i = stss->total_entries - 1; i >= 0; i--)
        {
                if(stss->table[i].sample <= frame) return stss->table[i].sample - 1;
        }

        return 0;
}

int64_t quicktime_get_keyframe_after(quicktime_t *file, int64_t frame, int track)
{
        quicktime_trak_t *trak = file->vtracks[track].track;
        quicktime_stss_t *stss = &trak->mdia.minf.stbl.stss;
        int i;





// Offset 1
        frame++;


        for(i = 0; i < stss->total_entries; i++)
        {
                if(stss->table[i].sample >= frame) return stss->table[i].sample - 1;
        }

        return 0;
}

void quicktime_insert_keyframe(quicktime_t *file, int64_t frame, int track)
{
        quicktime_trak_t *trak = file->vtracks[track].track;
        quicktime_stss_t *stss = &trak->mdia.minf.stbl.stss;
        int i;

// Set keyframe flag in idx1 table.
// Only possible in the first RIFF.  After that, there's no keyframe support.
        if(file->use_avi && file->total_riffs == 1)
                quicktime_set_idx1_keyframe(file, 
                        trak,
                        frame);

// Offset 1
        frame++;


// Get the keyframe greater or equal to new frame
        for(i = 0; i < stss->total_entries; i++)
        {
                if(stss->table[i].sample >= frame) break;
        }

// Expand table
        if(stss->entries_allocated <= stss->total_entries)
        {
                stss->entries_allocated *= 2;
                stss->table = realloc(stss->table, sizeof(quicktime_stss_table_t) * stss->entries_allocated);
        }

// Insert before existing frame
        if(i < stss->total_entries)
        {
                if(stss->table[i].sample > frame)
                {
                        int j, k;
                        for(j = stss->total_entries, k = stss->total_entries - 1;
                                k >= i;
                                j--, k--)
                        {
                                stss->table[j] = stss->table[k];
                        }
                        stss->table[i].sample = frame;
                }
        }
        else
// Insert after last frame
                stss->table[i].sample = frame;

        stss->total_entries++;
}