X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=mp4.c;h=1b387534d6adcbca4521472d473ebad49c7973cb;hb=b3ac1dc38bb8366ece6cbaf2adf95e964e0295c7;hp=3e7a74a88d4c3c2c401fc77947c77296045c8d1f;hpb=5f123ac45aed8c3480e8211b513cf9b6bd7eb2ab;p=paraslash.git

diff --git a/mp4.c b/mp4.c
index 3e7a74a8..1b387534 100644
--- a/mp4.c
+++ b/mp4.c
@@ -52,11 +52,8 @@ struct mp4 {
 	uint8_t last_atom;
 	uint64_t file_size;
 
-	uint32_t error;
-
 	/* incremental track index while reading the file */
 	int32_t total_tracks;
-
 	/* track data */
 	struct mp4_track *track[MAX_TRACKS];
 
@@ -64,11 +61,6 @@ struct mp4 {
 	struct mp4_metadata meta;
 };
 
-int32_t mp4_total_tracks(const struct mp4 *f)
-{
-	return f->total_tracks;
-}
-
 /*
  * Returns -1, 0, or 1 on errors/EOF/success. Partial reads followed by EOF or
  * read errors are treated as errors.
@@ -180,16 +172,16 @@ enum atoms {
 	ATOM_MVHD = 131,
 	ATOM_TKHD = 132,
 	ATOM_TREF = 133,
-	ATOM_MDHD = 134,
+	ATOM_MDHD = 134, /* track header */
 	ATOM_VMHD = 135,
 	ATOM_SMHD = 136,
 	ATOM_HMHD = 137,
-	ATOM_STSD = 138,
-	ATOM_STTS = 139,
-	ATOM_STSZ = 140,
+	ATOM_STSD = 138, /* sample description box */
+	ATOM_STTS = 139, /* time to sample box */
+	ATOM_STSZ = 140, /* sample size box */
 	ATOM_STZ2 = 141,
-	ATOM_STCO = 142,
-	ATOM_STSC = 143,
+	ATOM_STCO = 142, /* chunk offset box */
+	ATOM_STSC = 143, /* sample to chunk box */
 	ATOM_MP4A = 144,
 	ATOM_MP4V = 145,
 	ATOM_MP4S = 146,
@@ -445,18 +437,6 @@ static int32_t set_position(struct mp4 *f, int64_t position)
 	return 0;
 }
 
-static void track_add(struct mp4 *f)
-{
-	f->total_tracks++;
-
-	if (f->total_tracks > MAX_TRACKS) {
-		f->total_tracks = 0;
-		f->error++;
-		return;
-	}
-	f->track[f->total_tracks - 1] = para_calloc(sizeof(struct mp4_track));
-}
-
 static int read_stsz(struct mp4 *f)
 {
 	int ret;
@@ -870,34 +850,22 @@ static int32_t read_meta(struct mp4 *f, uint64_t size)
 	return 1;
 }
 
-static int32_t atom_read(struct mp4 *f, int32_t size, uint8_t atom_type)
+static int atom_read(struct mp4 *f, uint64_t size, uint8_t atom_type)
 {
 	uint64_t dest_position = get_position(f) + size - 8;
-	if (atom_type == ATOM_STSZ) {
-		/* sample size box */
-		read_stsz(f);
-	} else if (atom_type == ATOM_STTS) {
-		/* time to sample box */
-		read_stts(f);
-	} else if (atom_type == ATOM_STSC) {
-		/* sample to chunk box */
-		read_stsc(f);
-	} else if (atom_type == ATOM_STCO) {
-		/* chunk offset box */
-		read_stco(f);
-	} else if (atom_type == ATOM_STSD) {
-		/* sample description box */
-		read_stsd(f);
-	} else if (atom_type == ATOM_MDHD) {
-		/* track header */
-		read_mdhd(f);
-	} else if (atom_type == ATOM_META) {
-		/* iTunes Metadata box */
-		read_meta(f, size);
-	}
+	int ret = 1; /* return success for atoms we don't care about */
 
+	switch (atom_type) {
+	case ATOM_STSZ: ret = read_stsz(f); break;
+	case ATOM_STTS: ret = read_stts(f); break;
+	case ATOM_STSC: ret = read_stsc(f); break;
+	case ATOM_STCO: ret = read_stco(f); break;
+	case ATOM_STSD: ret = read_stsd(f); break;
+	case ATOM_MDHD: ret = read_mdhd(f); break;
+	case ATOM_META: ret = read_meta(f, size); break;
+	}
 	set_position(f, dest_position);
-	return 0;
+	return ret;
 }
 
 /* parse atoms that are sub atoms of other atoms */
@@ -916,25 +884,31 @@ static int parse_sub_atoms(struct mp4 *f, uint64_t total_size, int meta_only)
 		if (size == 0)
 			return -1;
 		counted_size += size;
-		/* we're starting to read a new track, update index,
-		 * so that all data and tables get written in the right place
-		 */
-		if (atom_type == ATOM_TRAK)
-			track_add(f);
+		if (atom_type == ATOM_TRAK) {
+			if (f->total_tracks >= MAX_TRACKS)
+				return -1;
+			f->total_tracks++;
+			f->track[f->total_tracks - 1] = para_calloc(
+				sizeof(struct mp4_track));
+		}
 		/* parse subatoms */
 		if (meta_only && !need_parse_when_meta_only(atom_type)) {
 			set_position(f, get_position(f) + size - header_size);
 		} else if (atom_type < SUBATOMIC) {
-			parse_sub_atoms(f, size - header_size, meta_only);
+			ret = parse_sub_atoms(f, size - header_size, meta_only);
+			if (ret <= 0)
+				return ret;
 		} else {
-			atom_read(f, (uint32_t) size, atom_type);
+			ret = atom_read(f, size, atom_type);
+			if (ret <= 0)
+				return ret;
 		}
 	}
 	return 1;
 }
 
 /* parse root atoms */
-static int32_t parse_atoms(struct mp4 *f, int meta_only)
+static int parse_atoms(struct mp4 *f, int meta_only)
 {
 	int ret;
 	uint64_t size;
@@ -956,7 +930,9 @@ static int32_t parse_atoms(struct mp4 *f, int meta_only)
 		if (meta_only && !need_parse_when_meta_only(atom_type)) {
 			set_position(f, get_position(f) + size - header_size);
 		} else if (atom_type < SUBATOMIC) {
-			parse_sub_atoms(f, size - header_size, meta_only);
+			ret = parse_sub_atoms(f, size - header_size, meta_only);
+			if (ret <= 0)
+				return ret;
 		} else {
 			/* skip this atom */
 			set_position(f, get_position(f) + size - header_size);
@@ -967,13 +943,14 @@ static int32_t parse_atoms(struct mp4 *f, int meta_only)
 
 struct mp4 *mp4_open_read(const struct mp4_callback *cb)
 {
+	int ret;
 	struct mp4 *f = para_calloc(sizeof(struct mp4));
 
 	f->cb = cb;
-	parse_atoms(f, 0);
-	if (f->error) {
+	ret = parse_atoms(f, 0);
+	if (ret < 0) {
 		free(f);
-		f = NULL;
+		return NULL;
 	}
 	return f;
 }
@@ -1085,24 +1062,11 @@ static int32_t sample_range_size(const struct mp4 *f, int32_t track,
 	return total;
 }
 
-static int32_t sample_to_offset(const struct mp4 *f, int32_t track,
-		int32_t sample)
-{
-	int32_t chunk, chunk_sample, chunk_offset1, chunk_offset2;
-
-	chunk_of_sample(f, track, sample, &chunk_sample, &chunk);
-
-	chunk_offset1 = chunk_to_offset(f, track, chunk);
-	chunk_offset2 = chunk_offset1 + sample_range_size(f,
-		track, chunk_sample, sample);
-	return chunk_offset2;
-}
-
 /**
  * Return the number of milliseconds of the given track.
  *
  * \param f As returned by \ref mp4_open_read(), must not be NULL.
- * \param track Between zero and the value returned by \ref mp4_total_tracks().
+ * \param track Between zero and the value returned by \ref mp4_get_total_tracks().
  *
  * The function returns zero if the audio file is of zero length or contains a
  * corrupt track header.
@@ -1116,6 +1080,11 @@ uint64_t mp4_get_duration(const struct mp4 *f, int32_t track)
 	return t->duration * 1000 / t->timeScale;
 }
 
+int32_t mp4_get_total_tracks(const struct mp4 *f)
+{
+	return f->total_tracks;
+}
+
 /**
  * Check whether the given track number corresponds to an audio track.
  *
@@ -1132,7 +1101,11 @@ bool mp4_is_audio_track(const struct mp4 *f, int32_t track)
 
 void mp4_set_sample_position(struct mp4 *f, int32_t track, int32_t sample)
 {
-	int32_t offset = sample_to_offset(f, track, sample);
+	int32_t offset, chunk, chunk_sample;
+
+	chunk_of_sample(f, track, sample, &chunk_sample, &chunk);
+	offset = chunk_to_offset(f, track, chunk)
+		+ sample_range_size(f, track, chunk_sample, sample);
 	set_position(f, offset);
 }
 
@@ -1168,13 +1141,14 @@ int32_t mp4_num_samples(const struct mp4 *f, int32_t track)
 
 struct mp4 *mp4_open_meta(const struct mp4_callback *cb)
 {
+	int ret;
 	struct mp4 *f = para_calloc(sizeof(struct mp4));
 
 	f->cb = cb;
-	parse_atoms(f, 1);
-	if (f->error) {
+	ret = parse_atoms(f, 1);
+	if (ret < 0) {
 		free(f);
-		f = NULL;
+		return NULL;
 	}
 	return f;
 }