Skip XING/VBRI frame when decoding
Don't send the XING/VBRI frame to the decoder, as it will result in
extra data being output. Also clean up the XING seeker code a bit.
Change-Id: I714a94180edae9bedc1bc0c96bf382fe6f928ac6
diff --git a/media/libstagefright/MP3Extractor.cpp b/media/libstagefright/MP3Extractor.cpp
index 2215c07..69209b5 100644
--- a/media/libstagefright/MP3Extractor.cpp
+++ b/media/libstagefright/MP3Extractor.cpp
@@ -317,6 +317,13 @@
mSeeker = VBRISeeker::CreateFromSource(mDataSource, post_id3_pos);
}
+ if (mSeeker != NULL) {
+ // While it is safe to send the XING/VBRI frame to the decoder, this will
+ // result in an extra 1152 samples being output. The real first frame to
+ // decode is after the XING/VBRI frame, so skip there.
+ mFirstFramePos += frame_size;
+ }
+
int64_t durationUs;
if (mSeeker == NULL || !mSeeker->getDuration(&durationUs)) {
diff --git a/media/libstagefright/VBRISeeker.cpp b/media/libstagefright/VBRISeeker.cpp
index 6ac5a83..bcba874 100644
--- a/media/libstagefright/VBRISeeker.cpp
+++ b/media/libstagefright/VBRISeeker.cpp
@@ -92,7 +92,7 @@
}
sp<VBRISeeker> seeker = new VBRISeeker;
- seeker->mBasePos = post_id3_pos;
+ seeker->mBasePos = post_id3_pos + frameSize;
seeker->mDurationUs = durationUs;
off64_t offset = post_id3_pos;
diff --git a/media/libstagefright/XINGSeeker.cpp b/media/libstagefright/XINGSeeker.cpp
index e36d619..8c99c76 100644
--- a/media/libstagefright/XINGSeeker.cpp
+++ b/media/libstagefright/XINGSeeker.cpp
@@ -15,35 +15,13 @@
*/
#include "include/XINGSeeker.h"
+#include "include/avc_utils.h"
#include <media/stagefright/DataSource.h>
#include <media/stagefright/Utils.h>
namespace android {
-static bool parse_xing_header(
- const sp<DataSource> &source, off64_t first_frame_pos,
- int32_t *frame_number = NULL, int32_t *byte_number = NULL,
- unsigned char *table_of_contents = NULL, bool *toc_is_valid = NULL,
- int32_t *quality_indicator = NULL, int64_t *duration = NULL);
-
-// static
-sp<XINGSeeker> XINGSeeker::CreateFromSource(
- const sp<DataSource> &source, off64_t first_frame_pos) {
- sp<XINGSeeker> seeker = new XINGSeeker;
-
- seeker->mFirstFramePos = first_frame_pos;
-
- if (!parse_xing_header(
- source, first_frame_pos,
- NULL, &seeker->mSizeBytes, seeker->mTOC, &seeker->mTOCValid,
- NULL, &seeker->mDurationUs)) {
- return NULL;
- }
-
- return seeker;
-}
-
XINGSeeker::XINGSeeker()
: mDurationUs(-1),
mSizeBytes(0) {
@@ -91,60 +69,50 @@
return true;
}
-static bool parse_xing_header(
- const sp<DataSource> &source, off64_t first_frame_pos,
- int32_t *frame_number, int32_t *byte_number,
- unsigned char *table_of_contents, bool *toc_valid,
- int32_t *quality_indicator,
- int64_t *duration) {
- if (frame_number) {
- *frame_number = 0;
- }
- if (byte_number) {
- *byte_number = 0;
- }
- if (toc_valid) {
- *toc_valid = false;
- }
- if (quality_indicator) {
- *quality_indicator = 0;
- }
- if (duration) {
- *duration = 0;
- }
+// static
+sp<XINGSeeker> XINGSeeker::CreateFromSource(
+ const sp<DataSource> &source, off64_t first_frame_pos) {
+ sp<XINGSeeker> seeker = new XINGSeeker;
+
+ seeker->mFirstFramePos = first_frame_pos;
+
+ ALOGI("xingseeker first frame pos: %lld", first_frame_pos);
+
+ seeker->mSizeBytes = 0;
+ seeker->mTOCValid = false;
+ seeker->mDurationUs = 0;
uint8_t buffer[4];
int offset = first_frame_pos;
if (source->readAt(offset, &buffer, 4) < 4) { // get header
- return false;
+ return NULL;
}
offset += 4;
- uint8_t id, layer, sr_index, mode;
- layer = (buffer[1] >> 1) & 3;
- id = (buffer[1] >> 3) & 3;
- sr_index = (buffer[2] >> 2) & 3;
- mode = (buffer[3] >> 6) & 3;
- if (layer == 0) {
- return false;
+ int header = U32_AT(buffer);;
+ size_t xingframesize = 0;
+ int sampling_rate = 0;
+ int num_channels;
+ int samples_per_frame = 0;
+ if (!GetMPEGAudioFrameSize(header, &xingframesize, &sampling_rate, &num_channels,
+ NULL, &samples_per_frame)) {
+ return NULL;
}
- if (id == 1) {
- return false;
- }
- if (sr_index == 3) {
- return false;
- }
+ seeker->mFirstFramePos += xingframesize;
+
+ uint8_t version = (buffer[1] >> 3) & 3;
+
// determine offset of XING header
- if(id&1) { // mpeg1
- if (mode != 3) offset += 32;
+ if(version & 1) { // mpeg1
+ if (num_channels != 1) offset += 32;
else offset += 17;
- } else { // mpeg2
- if (mode != 3) offset += 17;
+ } else { // mpeg 2 or 2.5
+ if (num_channels != 1) offset += 17;
else offset += 9;
}
if (source->readAt(offset, &buffer, 4) < 4) { // XING header ID
- return false;
+ return NULL;
}
offset += 4;
// Check XING ID
@@ -152,73 +120,50 @@
|| (buffer[2] != 'n') || (buffer[3] != 'g')) {
if ((buffer[0] != 'I') || (buffer[1] != 'n')
|| (buffer[2] != 'f') || (buffer[3] != 'o')) {
- return false;
+ return NULL;
}
}
if (source->readAt(offset, &buffer, 4) < 4) { // flags
- return false;
+ return NULL;
}
offset += 4;
uint32_t flags = U32_AT(buffer);
if (flags & 0x0001) { // Frames field is present
if (source->readAt(offset, buffer, 4) < 4) {
- return false;
+ return NULL;
}
- if (frame_number) {
- *frame_number = U32_AT(buffer);
- }
- int32_t frame = U32_AT(buffer);
- // Samples per Frame: 1. index = MPEG Version ID, 2. index = Layer
- const int samplesPerFrames[2][3] =
- {
- { 384, 1152, 576 }, // MPEG 2, 2.5: layer1, layer2, layer3
- { 384, 1152, 1152 }, // MPEG 1: layer1, layer2, layer3
- };
- // sampling rates in hertz: 1. index = MPEG Version ID, 2. index = sampling rate index
- const int samplingRates[4][3] =
- {
- { 11025, 12000, 8000, }, // MPEG 2.5
- { 0, 0, 0, }, // reserved
- { 22050, 24000, 16000, }, // MPEG 2
- { 44100, 48000, 32000, } // MPEG 1
- };
- if (duration) {
- *duration = (int64_t)frame * samplesPerFrames[id&1][3-layer] * 1000000LL
- / samplingRates[id][sr_index];
- }
+ int32_t frames = U32_AT(buffer);
+ seeker->mDurationUs = (int64_t)frames * samples_per_frame * 1000000LL / sampling_rate;
offset += 4;
}
if (flags & 0x0002) { // Bytes field is present
- if (byte_number) {
- if (source->readAt(offset, buffer, 4) < 4) {
- return false;
- }
- *byte_number = U32_AT(buffer);
+ if (source->readAt(offset, buffer, 4) < 4) {
+ return NULL;
}
+ seeker->mSizeBytes = U32_AT(buffer);
offset += 4;
}
if (flags & 0x0004) { // TOC field is present
- if (table_of_contents) {
- if (source->readAt(offset + 1, table_of_contents, 99) < 99) {
- return false;
- }
- if (toc_valid) {
- *toc_valid = true;
- }
+ if (source->readAt(offset + 1, seeker->mTOC, 99) < 99) {
+ return NULL;
}
+ seeker->mTOCValid = true;
offset += 100;
}
+
+#if 0
if (flags & 0x0008) { // Quality indicator field is present
- if (quality_indicator) {
- if (source->readAt(offset, buffer, 4) < 4) {
- return false;
- }
- *quality_indicator = U32_AT(buffer);
+ if (source->readAt(offset, buffer, 4) < 4) {
+ return NULL;
}
+ // do something with the quality indicator
+ offset += 4;
}
- return true;
+#endif
+
+ return seeker;
}
} // namespace android