isom_read.c

一个用于智能手机的多媒体库适合S60 WinCE的跨平台开发库

	if (!IsMP4Description(entry->type)) return 0;
	return entry->type;
}

//Get the HandlerDescription name. 
GF_EXPORT
GF_Err gf_isom_get_handler_name(GF_ISOFile *the_file, u32 trackNumber, const char **outName)
{
	GF_TrackBox *trak;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak || !outName) return GF_BAD_PARAM;
	*outName = trak->Media->handler->nameUTF8;
	return GF_OK;
}

//Check the DataReferences of this track
GF_EXPORT
GF_Err gf_isom_check_data_reference(GF_ISOFile *the_file, u32 trackNumber, u32 StreamDescriptionIndex)
{
	GF_Err e;
	u32 drefIndex;
	GF_TrackBox *trak;

	if (!StreamDescriptionIndex || !trackNumber) return GF_BAD_PARAM;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return GF_BAD_PARAM;

	e = Media_GetSampleDesc(trak->Media, StreamDescriptionIndex , NULL, &drefIndex);
	if (e) return e;
	if (!drefIndex) return GF_BAD_PARAM;
	return Media_CheckDataEntry(trak->Media, drefIndex);
}

//get the location of the data. If URL && URN are NULL, the data is in this file
GF_EXPORT
GF_Err gf_isom_get_data_reference(GF_ISOFile *the_file, u32 trackNumber, u32 StreamDescriptionIndex, const char **outURL, const char **outURN)
{
	GF_TrackBox *trak;
	GF_DataEntryURLBox *url;
	GF_DataEntryURNBox *urn;
	u32 drefIndex;
	GF_Err e;

	if (!StreamDescriptionIndex || !trackNumber) return GF_BAD_PARAM;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return GF_BAD_PARAM;

	e = Media_GetSampleDesc(trak->Media, StreamDescriptionIndex , NULL, &drefIndex);
	if (e) return e;
	if (!drefIndex) return GF_BAD_PARAM;

	url = (GF_DataEntryURLBox*)gf_list_get(trak->Media->information->dataInformation->dref->boxList, drefIndex - 1);
	if (!url) return GF_ISOM_INVALID_FILE;

	*outURL = *outURN = NULL;
	if (url->type == GF_ISOM_BOX_TYPE_URL) {
		*outURL = url->location;
		*outURN = NULL;
	} else if (url->type == GF_ISOM_BOX_TYPE_URN) {
		urn = (GF_DataEntryURNBox *) url;
		*outURN = urn->nameURN;
		*outURL = urn->location;
	} else {
		*outURN = NULL;
		*outURL = NULL;
	}
	return GF_OK;
}

//Get the number of samples
//return 0 if error or empty
GF_EXPORT
u32 gf_isom_get_sample_count(GF_ISOFile *the_file, u32 trackNumber)
{
	GF_TrackBox *trak;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return 0;
	return trak->Media->information->sampleTable->SampleSize->sampleCount;
}

u32 gf_isom_get_constant_sample_size(GF_ISOFile *the_file, u32 trackNumber)
{
	GF_TrackBox *trak;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return 0;
	return trak->Media->information->sampleTable->SampleSize->sampleSize;
}

GF_EXPORT
Bool gf_isom_has_time_offset(GF_ISOFile *the_file, u32 trackNumber)
{
	u32 i;
	GF_CompositionOffsetBox *ctts;
	GF_DttsEntry *pe;
	GF_TrackBox *trak;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak || !trak->Media->information->sampleTable->CompositionOffset) return 0;

	//return true at the first offset found
	ctts = trak->Media->information->sampleTable->CompositionOffset;
	i=0;
	while ((pe = (GF_DttsEntry*)gf_list_enum(ctts->entryList, &i))) {
		if (pe->decodingOffset && pe->sampleCount) return 1;
	}
	return 0;
}

GF_EXPORT
Bool gf_isom_has_sync_shadows(GF_ISOFile *the_file, u32 trackNumber)
{
	GF_TrackBox *trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return 0;
	if (!trak->Media->information->sampleTable->ShadowSync) return 0;
	if (gf_list_count(trak->Media->information->sampleTable->ShadowSync->entries) ) return 1;
	return 0;
}

Bool gf_isom_has_sample_dependency(GF_ISOFile *the_file, u32 trackNumber)
{
	GF_TrackBox *trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return 0;
	if (!trak->Media->information->sampleTable->SampleDep) return 0;
	return 1;
}

//return a sample give its number, and set the SampleDescIndex of this sample
//this index allows to retrieve the stream description if needed (2 media in 1 track)
//return NULL if error
GF_EXPORT
GF_ISOSample *gf_isom_get_sample(GF_ISOFile *the_file, u32 trackNumber, u32 sampleNumber, u32 *sampleDescriptionIndex)
{
	GF_Err e;
	u32 descIndex;
	GF_TrackBox *trak;
	GF_ISOSample *samp;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return NULL;

	if (!sampleNumber) return NULL;
	samp = gf_isom_sample_new();
	if (!samp) return NULL;
	e = Media_GetSample(trak->Media, sampleNumber, &samp, &descIndex, 0, NULL);
	if (e) {
		gf_isom_set_last_error(the_file, e);
		gf_isom_sample_del(&samp);
		return NULL;
	}
	if (sampleDescriptionIndex) *sampleDescriptionIndex = descIndex;
	
	return samp;
}

GF_EXPORT
u32 gf_isom_get_sample_duration(GF_ISOFile *the_file, u32 trackNumber, u32 sampleNumber)
{
	u64 dur;
	u64 dts;
	GF_TrackBox *trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak || !sampleNumber) return 0;

	stbl_GetSampleDTS(trak->Media->information->sampleTable->TimeToSample, sampleNumber, &dur);
	if (sampleNumber == trak->Media->information->sampleTable->SampleSize->sampleCount) {
		return (u32) (trak->Media->mediaHeader->duration - dur);
	} 
	
	stbl_GetSampleDTS(trak->Media->information->sampleTable->TimeToSample, sampleNumber+1, &dts);
	return (u32) (dts - dur);
}

//same as gf_isom_get_sample but doesn't fetch media data
GF_EXPORT
GF_ISOSample *gf_isom_get_sample_info(GF_ISOFile *the_file, u32 trackNumber, u32 sampleNumber, u32 *sampleDescriptionIndex, u64 *data_offset)
{
	GF_Err e;
	GF_TrackBox *trak;
	GF_ISOSample *samp;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return NULL;

	if (!sampleNumber) return NULL;
	samp = gf_isom_sample_new();
	if (!samp) return NULL;
	e = Media_GetSample(trak->Media, sampleNumber, &samp, sampleDescriptionIndex, 1, data_offset);
	if (e) {
		gf_isom_set_last_error(the_file, e);
		gf_isom_sample_del(&samp);
		return NULL;
	}
	return samp;
}

//same as gf_isom_get_sample but doesn't fetch media data
GF_EXPORT
u64 gf_isom_get_sample_dts(GF_ISOFile *the_file, u32 trackNumber, u32 sampleNumber)
{
	u64 dts;
	GF_TrackBox *trak;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return 0;

	if (!sampleNumber) return 0;
	if (stbl_GetSampleDTS(trak->Media->information->sampleTable->TimeToSample, sampleNumber, &dts) != GF_OK) return 0;
	return dts;
}


GF_EXPORT
Bool gf_isom_is_self_contained(GF_ISOFile *the_file, u32 trackNumber, u32 sampleDescriptionIndex)
{
	GF_TrackBox *trak;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return 0;
	return Media_IsSelfContained(trak->Media, sampleDescriptionIndex);
}


//return a sample given a desired display time IN MEDIA TIME SCALE
//and set the StreamDescIndex of this sample
//this index allows to retrieve the stream description if needed (2 media in 1 track)
//return NULL if error
//WARNING: the sample may not be sync even though the sync was requested (depends on the media)
GF_EXPORT
GF_Err gf_isom_get_sample_for_media_time(GF_ISOFile *the_file, u32 trackNumber, u64 desiredTime, u32 *StreamDescriptionIndex, u8 SearchMode, GF_ISOSample **sample, u32 *SampleNum)
{
	GF_Err e;
	u32 sampleNumber, prevSampleNumber, syncNum, shadowSync;
	GF_TrackBox *trak;
	GF_ISOSample *shadow;
	GF_SampleTableBox *stbl;
	u8 useShadow, IsSync;

	if (!sample) return GF_BAD_PARAM;

	if (SampleNum) *SampleNum = 0;
	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return GF_BAD_PARAM;

	stbl = trak->Media->information->sampleTable;
	
	e = findEntryForTime(stbl, desiredTime, 1, &sampleNumber, &prevSampleNumber);
	if (e) return e;

	//if no shadow table, reset to sync only
	useShadow = 0;
	if (!stbl->ShadowSync && (SearchMode == GF_ISOM_SEARCH_SYNC_SHADOW))
		SearchMode = GF_ISOM_SEARCH_SYNC_BACKWARD;

	//if no syncTable, disable syncSearching, as all samples ARE sync
	if (! trak->Media->information->sampleTable->SyncSample) {
		if (SearchMode == GF_ISOM_SEARCH_SYNC_FORWARD) SearchMode = GF_ISOM_SEARCH_FORWARD;
		if (SearchMode == GF_ISOM_SEARCH_SYNC_BACKWARD) SearchMode = GF_ISOM_SEARCH_BACKWARD;
	}

	//not found, return EOF or browse backward
	if (!sampleNumber && !prevSampleNumber) {
		if (SearchMode == GF_ISOM_SEARCH_SYNC_BACKWARD || SearchMode == GF_ISOM_SEARCH_BACKWARD) {
			sampleNumber = trak->Media->information->sampleTable->SampleSize->sampleCount;
		}
		if (!sampleNumber) return GF_EOS;
	}

	//check in case we have the perfect sample
	IsSync = 0;

	//according to the direction adjust the sampleNum value
	switch (SearchMode) {
	case GF_ISOM_SEARCH_SYNC_FORWARD:
		IsSync = 1;
	case GF_ISOM_SEARCH_FORWARD:
		//not the exact one
		if (!sampleNumber) {
			if (prevSampleNumber != stbl->SampleSize->sampleCount) {
				sampleNumber = prevSampleNumber + 1;
			} else {
				sampleNumber = prevSampleNumber;
			}
		}
		break;

	//if dummy mode, reset to default browsing
	case GF_ISOM_SEARCH_SYNC_BACKWARD:
		IsSync = 1;
	case GF_ISOM_SEARCH_SYNC_SHADOW:
	case GF_ISOM_SEARCH_BACKWARD:
	default:
		//first case, not found....
		if (!sampleNumber && !prevSampleNumber) {
			sampleNumber = stbl->SampleSize->sampleCount;
		} else if (!sampleNumber) {
			sampleNumber = prevSampleNumber;
		}
		break;
	}

	//get the sync sample num
	if (IsSync) {
		//get the SyncNumber
		e = Media_FindSyncSample(trak->Media->information->sampleTable,
						sampleNumber, &syncNum, SearchMode);
		if (e) return e;
		if (syncNum) sampleNumber = syncNum;
		syncNum = 0;
	}
	//if we are in shadow mode, get the previous sync sample
	//in case we can't find a good SyncShadow
	else if (SearchMode == GF_ISOM_SEARCH_SYNC_SHADOW) {
		//get the SyncNumber
		e = Media_FindSyncSample(trak->Media->information->sampleTable,
						sampleNumber, &syncNum, GF_ISOM_SEARCH_SYNC_BACKWARD);
		if (e) return e;
	}


	//OK sampleNumber is exactly the sample we need (except for shadow)
	
	*sample = gf_isom_sample_new();
	if (*sample == NULL) return GF_OUT_OF_MEM;

	//we are in shadow mode, we need to browse both SyncSample and ShadowSyncSample to get
	//the desired sample...
	if (SearchMode == GF_ISOM_SEARCH_SYNC_SHADOW) {
		//get the shadowing number
		stbl_GetSampleShadow(stbl->ShadowSync, &sampleNumber, &shadowSync);
		//now sampleNumber is the closest previous shadowed sample.
		//1- If we have a closer sync sample, use it.
		//2- if the shadowSync is 0, we don't have any shadowing, use syncNum
		if ((sampleNumber < syncNum) || (!shadowSync)) {
			sampleNumber = syncNum;
		} else {
		//otherwise, we have a better alternate sample in the shadowSync for this sample
			useShadow = 1;
		}
	}

	e = Media_GetSample(trak->Media, sampleNumber, sample, StreamDescriptionIndex, 0, NULL);
	if (e) {
		gf_isom_sample_del(sample);
		return e;
	}
	//optionally get the sample number
	if (SampleNum) *SampleNum = sampleNumber;

	//in shadow mode, we only get the data of the shadowing sample !
	if (useShadow) {
		//we have to use StreamDescriptionIndex in case the sample data is in another desc
		//though this is unlikely as non optimized...
		shadow = gf_isom_get_sample(the_file, trackNumber, shadowSync, StreamDescriptionIndex);
		//if no sample, the shadowSync is broken, return the sample
		if (!shadow) return GF_OK;
		(*sample)->IsRAP = 1;
		free((*sample)->data);
		(*sample)->dataLength = shadow->dataLength;
		(*sample)->data = shadow->data;
		//set data length to 0 to keep the buffer alive...
		shadow->dataLength = 0;
		gf_isom_sample_del(&shadow);
	}
	return GF_OK;
}

GF_EXPORT
GF_Err gf_isom_get_sample_for_movie_time(GF_ISOFile *the_file, u32 trackNumber, u64 movieTime, u32 *StreamDescriptionIndex, u8 SearchMode, GF_ISOSample **sample, u32 *sampleNumber)
{
	GF_Err e;
	GF_TrackBox *trak;
	u64 mediaTime;
	s64 segStartTime, mediaOffset;
	u32 sampNum;
	u8 useEdit;

	trak = gf_isom_get_track_from_file(the_file, trackNumber);
	if (!trak) return GF_BAD_PARAM;

	if (*sample || !sample) return GF_BAD_PARAM;
	//check 0-duration tracks (BIFS and co). Check we're not searching forward
	if (!trak->Header->duration) {
		if (movieTime && ( (SearchMode == GF_ISOM_SEARCH_SYNC_FORWARD) || (SearchMode == GF_ISOM_SEARCH_FORWARD)) ) {
			*sample = NULL;
			if (sampleNumber) *sampleNumber = 0;
			*StreamDescriptionIndex = 0;
			return GF_EOS;
		}
	}
	else if (movieTime * trak->moov->mvhd->timeScale > trak->Header->duration * trak->Media->mediaHeader->timeScale) {
		*sample = NULL;
		if (sampleNumber) *sampleNumber = 0;
		*StreamDescriptionIndex = 0;
		return GF_EOS;
	}

	//get the media time for this movie time...
	mediaTime = segStartTime = 0;
	*StreamDescriptionIndex = 0;

	e = GetMediaTime(trak, movieTime, &mediaTime, &segStartTime, &mediaOffset, &useEdit);
	if (e) return e;

	/*here we check if we were playing or not and return no sample in normal search modes*/
	if (useEdit && mediaOffset == -1) {
		if ((SearchMode==GF_ISOM_SEARCH_FORWARD) || (SearchMode==GF_ISOM_SEARCH_BACKWARD)) {
			/*get next sample time in MOVIE timescale*/
			if (SearchMode==GF_ISOM_SEARCH_FORWARD) 
				e = GetNextMediaTime(trak, movieTime, &mediaTime);
			else
				e = GetPrevMediaTime(trak, movieTime, &mediaTime);
			if (e) return e;
			return gf_isom_get_sample_for_movie_time(the_file, trackNumber, (u32) mediaTime, StreamDescriptionIndex, GF_ISOM_SEARCH_SYNC_FORWARD, sample, sampleNumber);
		}
		if (sampleNumber) *sampleNumber = 0;
		*sample = gf_isom_sample_new();
		(*sample)->DTS = movieTime;
		return GF_OK;
	}
	/*dwell edit in non-sync mode, fetch next/prev sample depending on mode.
	Otherwise return the dwell entry*/
	if (useEdit==2) {
		if ((SearchMode==GF_ISOM_SEARCH_FORWARD) || (SearchMode==GF_ISOM_SEARCH_BACKWARD)) {
			/*get next sample time in MOVIE timescale*/
			if (SearchMode==GF_ISOM_SEARCH_FORWARD) 
				e = GetNextMediaTime(trak, movieTime, &mediaTime);
			else
				e = GetPrevMediaTime(trak, movieTime, &mediaTime);
			if (e) return e;
			return gf_isom_get_sample_for_movie_time(the_file, trackNumber, (u32) mediaTime, StreamDescriptionIndex, GF_ISOM_SEARCH_SYNC_FORWARD, sample, sampleNumber);
		}
	}

	//OK, we have a sample so fetch it
	e = gf_isom_get_sample_for_media_time(the_file, trackNumber, mediaTime, StreamDescriptionIndex, SearchMode, sample, &sampNum);
	if (e) return e;

	//OK, now the trick: we have to rebuild the time stamps, according 
	//to the media time scale (used by SLConfig) - add the edit start time but stay in 
	//the track TS
	if (useEdit) {
		u64 _ts = segStartTime;
		_ts *= trak->Media->mediaHeader->timeScale;
		_ts /= trak->moov->mvhd->timeScale;
		(*sample)->DTS += _ts;
		/*watchout, the sample fetched may be before the first sample in the edit list (when seeking)*/