generic-library/webm
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

mkvmuxer: Write Block key frames correctly.

Browse Source 
Per matroska Block Structure [1], for keyframes the flag should not be
set (unlike SimpleBlocks). For Blocks, keyframes is inferred by the
absence of ReferenceBlock element.

This CL fixes Issue #933 [2].

[1] http://www.matroska.org/technical/specs/index.html#block_structure
[2] https://code.google.com/p/webm/issues/detail?id=933

Change-Id: Ia3f811c3fe17fb4dededda2f6834cf7cf2d2e022
This commit is contained in:
Vignesh Venkatasubramanian
2015-05-21 17:14:04 -07:00
parent 5dd0e40dbd
commit c3550fdacf
4 changed files with 91 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

57
mkvmuxerutil.cpp
View File

@@ -36,7 +36,7 @@ namespace {
const int kDateElementSize = 8;
uint64 WriteBlock(IMkvWriter* writer, const Frame* const frame, int64 timecode,
uint64 duration) {
uint64 timecode_scale) {
uint64 block_additional_elem_size = 0;
uint64 block_addid_elem_size = 0;
uint64 block_more_payload_size = 0;
@@ -66,6 +66,15 @@ uint64 WriteBlock(IMkvWriter* writer, const Frame* const frame, int64 timecode,
EbmlElementSize(kMkvDiscardPadding, frame->discard_padding());
}
const uint64 reference_block_timestamp =
frame->reference_block_timestamp() / timecode_scale;
uint64 reference_block_elem_size = 0;
if (!frame->is_key()) {
reference_block_elem_size =
EbmlElementSize(kMkvReferenceBlock, reference_block_timestamp);
}
const uint64 duration = frame->duration() / timecode_scale;
uint64 block_duration_elem_size = 0;
if (duration > 0)
block_duration_elem_size = EbmlElementSize(kMkvBlockDuration, duration);
@@ -76,7 +85,7 @@ uint64 WriteBlock(IMkvWriter* writer, const Frame* const frame, int64 timecode,
const uint64 block_group_payload_size =
block_elem_size + block_additions_elem_size + block_duration_elem_size +
discard_padding_elem_size;
discard_padding_elem_size + reference_block_elem_size;
if (!WriteEbmlMasterElement(writer, kMkvBlockGroup,
block_group_payload_size)) {
@@ -92,10 +101,8 @@ uint64 WriteBlock(IMkvWriter* writer, const Frame* const frame, int64 timecode,
if (SerializeInt(writer, timecode, 2))
return 0;
uint64 flags = 0;
if (frame->is_key())
flags |= 0x80;
if (SerializeInt(writer, flags, 1))
// For a Block, flags is always 0.
if (SerializeInt(writer, 0, 1))
return 0;
if (writer->Write(frame->frame(), static_cast<uint32>(frame->length())))
@@ -119,18 +126,15 @@ uint64 WriteBlock(IMkvWriter* writer, const Frame* const frame, int64 timecode,
}
}
if (frame->discard_padding() != 0) {
if (WriteID(writer, kMkvDiscardPadding))
return 0;
if (frame->discard_padding() != 0 &&
!WriteEbmlElement(writer, kMkvDiscardPadding, frame->discard_padding())) {
return false;
}
const uint64 size = GetIntSize(frame->discard_padding());
if (WriteUInt(writer, size))
return false;
if (SerializeInt(writer, frame->discard_padding(),
static_cast<int32>(size))) {
return false;
}
if (!frame->is_key() &&
!WriteEbmlElement(writer, kMkvReferenceBlock,
reference_block_timestamp)) {
return false;
}
if (duration > 0 && !WriteEbmlElement(writer, kMkvBlockDuration, duration)) {
@@ -440,6 +444,23 @@ bool WriteEbmlElement(IMkvWriter* writer, uint64 type, uint64 value) {
return true;
}
bool WriteEbmlElement(IMkvWriter* writer, uint64 type, int64 value) {
if (!writer)
return false;
if (WriteID(writer, type))
return 0;
const uint64 size = GetIntSize(value);
if (WriteUInt(writer, size))
return false;
if (SerializeInt(writer, value, static_cast<int32>(size)))
return false;
return true;
}
bool WriteEbmlElement(IMkvWriter* writer, uint64 type, float value) {
if (!writer)
return false;
@@ -524,7 +545,7 @@ uint64 WriteFrame(IMkvWriter* writer, const Frame* const frame,
return frame->CanBeSimpleBlock()
? WriteSimpleBlock(writer, frame, relative_timecode)
: WriteBlock(writer, frame, relative_timecode,
frame->duration() / cluster->timecode_scale());
cluster->timecode_scale());
}
uint64 WriteVoidElement(IMkvWriter* writer, uint64 size) {