ref: 367d20be44225752b3974addd9789a821f88b692
dir: /common/mp4av/rfcisma.cpp/
/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is MPEG4IP.
*
* The Initial Developer of the Original Code is Cisco Systems Inc.
* Portions created by Cisco Systems Inc. are
* Copyright (C) Cisco Systems Inc. 2000-2002. All Rights Reserved.
*
* Contributor(s):
* Dave Mackie dmackie@cisco.com
*/
/*
* Notes:
* - file formatted with tabstops == 4 spaces
*/
#include <mp4av_common.h>
bool MP4AV_RfcIsmaConcatenator(
MP4FileHandle mp4File,
MP4TrackId mediaTrackId,
MP4TrackId hintTrackId,
u_int8_t samplesThisHint,
MP4SampleId* pSampleIds,
MP4Duration hintDuration,
u_int16_t maxPayloadSize)
{
// handle degenerate case
if (samplesThisHint == 0) {
return true;
}
u_int8_t auPayloadHdrSize;
// LATER would be more efficient if this were a parameter
u_int8_t mpeg4AudioType =
MP4GetTrackAudioMpeg4Type(mp4File, mediaTrackId);
if (mpeg4AudioType == MP4_MPEG4_CELP_AUDIO_TYPE) {
auPayloadHdrSize = 1;
} else {
auPayloadHdrSize = 2;
}
// construct the new hint
MP4AddRtpHint(mp4File, hintTrackId);
MP4AddRtpPacket(mp4File, hintTrackId, true);
u_int8_t payloadHeader[2];
u_int16_t numHdrBits = samplesThisHint * auPayloadHdrSize * 8;
payloadHeader[0] = numHdrBits >> 8;
payloadHeader[1] = numHdrBits & 0xFF;
MP4AddRtpImmediateData(mp4File, hintTrackId,
(u_int8_t*)&payloadHeader, sizeof(payloadHeader));
u_int8_t i;
// first the headers
for (i = 0; i < samplesThisHint; i++) {
MP4SampleId sampleId = pSampleIds[i];
u_int32_t sampleSize =
MP4GetSampleSize(mp4File, mediaTrackId, sampleId);
if (auPayloadHdrSize == 1) {
// AU payload header is 6 bits of size
// follow by 2 bits of the difference between sampleId's - 1
payloadHeader[0] = sampleSize << 2;
} else { // auPayloadHdrSize == 2
// AU payload header is 13 bits of size
// follow by 3 bits of the difference between sampleId's - 1
payloadHeader[0] = sampleSize >> 5;
payloadHeader[1] = (sampleSize & 0x1F) << 3;
}
if (i > 0) {
payloadHeader[auPayloadHdrSize - 1]
|= ((sampleId - pSampleIds[i-1]) - 1);
}
MP4AddRtpImmediateData(mp4File, hintTrackId,
(u_int8_t*)&payloadHeader, auPayloadHdrSize);
}
// then the samples
for (i = 0; i < samplesThisHint; i++) {
MP4SampleId sampleId = pSampleIds[i];
u_int32_t sampleSize =
MP4GetSampleSize(mp4File, mediaTrackId, sampleId);
MP4AddRtpSampleData(mp4File, hintTrackId, sampleId, 0, sampleSize);
}
// write the hint
MP4WriteRtpHint(mp4File, hintTrackId, hintDuration);
return true;
}
bool MP4AV_RfcIsmaFragmenter(
MP4FileHandle mp4File,
MP4TrackId mediaTrackId,
MP4TrackId hintTrackId,
MP4SampleId sampleId,
u_int32_t sampleSize,
MP4Duration sampleDuration,
u_int16_t maxPayloadSize)
{
MP4AddRtpHint(mp4File, hintTrackId);
MP4AddRtpPacket(mp4File, hintTrackId, false);
// Note: CELP is never fragmented
// so we assume the two byte AAC-hbr payload header
u_int8_t payloadHeader[4];
payloadHeader[0] = 0;
payloadHeader[1] = 16;
payloadHeader[2] = sampleSize >> 5;
payloadHeader[3] = (sampleSize & 0x1F) << 3;
MP4AddRtpImmediateData(mp4File, hintTrackId,
(u_int8_t*)&payloadHeader, sizeof(payloadHeader));
u_int16_t sampleOffset = 0;
u_int16_t fragLength = maxPayloadSize - 4;
do {
MP4AddRtpSampleData(mp4File, hintTrackId,
sampleId, sampleOffset, fragLength);
sampleOffset += fragLength;
if (sampleSize - sampleOffset > maxPayloadSize) {
fragLength = maxPayloadSize;
MP4AddRtpPacket(mp4File, hintTrackId, false);
} else {
fragLength = sampleSize - sampleOffset;
if (fragLength) {
MP4AddRtpPacket(mp4File, hintTrackId, true);
}
}
} while (sampleOffset < sampleSize);
MP4WriteRtpHint(mp4File, hintTrackId, sampleDuration);
return true;
}
extern "C" bool MP4AV_RfcIsmaHinter(
MP4FileHandle mp4File,
MP4TrackId mediaTrackId,
bool interleave,
u_int16_t maxPayloadSize)
{
// gather information, and check for validity
u_int32_t numSamples =
MP4GetTrackNumberOfSamples(mp4File, mediaTrackId);
if (numSamples == 0) {
return false;
}
u_int32_t timeScale =
MP4GetTrackTimeScale(mp4File, mediaTrackId);
if (timeScale == 0) {
return false;
}
u_int8_t audioType =
MP4GetTrackAudioType(mp4File, mediaTrackId);
if (audioType != MP4_MPEG4_AUDIO_TYPE
&& !MP4_IS_AAC_AUDIO_TYPE(audioType)) {
return false;
}
u_int8_t mpeg4AudioType =
MP4GetTrackAudioMpeg4Type(mp4File, mediaTrackId);
if (audioType == MP4_MPEG4_AUDIO_TYPE) {
// check that track contains either MPEG-4 AAC or CELP
if (!MP4_IS_MPEG4_AAC_AUDIO_TYPE(mpeg4AudioType)
&& mpeg4AudioType != MP4_MPEG4_CELP_AUDIO_TYPE) {
return false;
}
}
MP4Duration sampleDuration =
MP4AV_GetAudioSampleDuration(mp4File, mediaTrackId);
if (sampleDuration == MP4_INVALID_DURATION) {
return false;
}
/* get the ES configuration */
u_int8_t* pConfig = NULL;
u_int32_t configSize;
uint8_t channels;
MP4GetTrackESConfiguration(mp4File, mediaTrackId, &pConfig, &configSize);
if (!pConfig) {
return false;
}
channels = MP4AV_AacConfigGetChannels(pConfig);
/* convert ES Config into ASCII form */
char* sConfig =
MP4BinaryToBase16(pConfig, configSize);
free(pConfig);
if (!sConfig) {
return false;
}
/* create the appropriate SDP attribute */
char* sdpBuf =
(char*)malloc(strlen(sConfig) + 256);
if (!sdpBuf) {
free(sConfig);
return false;
}
// now add the hint track
MP4TrackId hintTrackId =
MP4AddHintTrack(mp4File, mediaTrackId);
if (hintTrackId == MP4_INVALID_TRACK_ID) {
free(sConfig);
free(sdpBuf);
return false;
}
u_int8_t payloadNumber = MP4_SET_DYNAMIC_PAYLOAD;
char buffer[10];
if (channels != 1) {
snprintf(buffer, sizeof(buffer), "%u", channels);
}
MP4SetHintTrackRtpPayload(mp4File, hintTrackId,
"mpeg4-generic", &payloadNumber, 0,
channels != 1 ? buffer : NULL);
MP4Duration maxLatency;
if (mpeg4AudioType == MP4_MPEG4_CELP_AUDIO_TYPE) {
sprintf(sdpBuf,
"a=fmtp:%u "
"streamtype=5; profile-level-id=15; mode=CELP-vbr; config=%s; "
"SizeLength=6; IndexLength=2; IndexDeltaLength=2; Profile=0;"
"\015\012",
payloadNumber,
sConfig);
// 200 ms max latency for ISMA profile 1
maxLatency = timeScale / 5;
} else { // AAC
sprintf(sdpBuf,
"a=fmtp:%u "
"streamtype=5; profile-level-id=15; mode=AAC-hbr; config=%s; "
"SizeLength=13; IndexLength=3; IndexDeltaLength=3; Profile=1;"
"\015\012",
payloadNumber,
sConfig);
// 500 ms max latency for ISMA profile 1
maxLatency = timeScale / 2;
}
/* add this to the track's sdp */
MP4AppendHintTrackSdp(mp4File, hintTrackId, sdpBuf);
free(sConfig);
free(sdpBuf);
u_int32_t samplesPerPacket = 0;
if (interleave) {
u_int32_t maxSampleSize =
MP4GetTrackMaxSampleSize(mp4File, mediaTrackId);
// compute how many maximum size samples would fit in a packet
samplesPerPacket =
(maxPayloadSize - 2) / (maxSampleSize + 2);
// can't interleave if this number is 0 or 1
if (samplesPerPacket < 2) {
interleave = false;
}
}
bool rc;
if (interleave) {
u_int32_t samplesPerGroup = maxLatency / sampleDuration;
rc = MP4AV_AudioInterleaveHinter(
mp4File,
mediaTrackId,
hintTrackId,
sampleDuration,
samplesPerGroup / samplesPerPacket, // stride
samplesPerPacket, // bundle
maxPayloadSize,
MP4AV_RfcIsmaConcatenator);
} else {
rc = MP4AV_AudioConsecutiveHinter(
mp4File,
mediaTrackId,
hintTrackId,
sampleDuration,
2, // perPacketHeaderSize
2, // perSampleHeaderSize
maxLatency / sampleDuration, // maxSamplesPerPacket
maxPayloadSize,
MP4GetSampleSize,
MP4AV_RfcIsmaConcatenator,
MP4AV_RfcIsmaFragmenter);
}
if (!rc) {
MP4DeleteTrack(mp4File, hintTrackId);
return false;
}
return true;
}