ref: b00a2415ffe2895620baf6bae968d547cc723f21
dir: /common/mp4av/rfc2250.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 [email protected] */ /* * Notes: * - file formatted with tabstops == 4 spaces */ #include <mp4av_common.h> extern "C" bool MP4AV_Rfc2250Hinter( MP4FileHandle mp4File, MP4TrackId mediaTrackId, bool interleave, u_int16_t maxPayloadSize) { // RFC 2250 doesn't support interleaving if (interleave) { return false; } u_int32_t numSamples = MP4GetTrackNumberOfSamples(mp4File, mediaTrackId); if (numSamples == 0) { return false; } u_int8_t audioType = MP4GetTrackAudioType(mp4File, mediaTrackId); if (!MP4_IS_MP3_AUDIO_TYPE(audioType)) { return false; } MP4Duration sampleDuration = MP4AV_GetAudioSampleDuration(mp4File, mediaTrackId); if (sampleDuration == MP4_INVALID_DURATION) { return false; } MP4TrackId hintTrackId = MP4AddHintTrack(mp4File, mediaTrackId); if (hintTrackId == MP4_INVALID_TRACK_ID) { return false; } u_int8_t payloadNumber = MP4_SET_DYNAMIC_PAYLOAD; // use dynamic payload number if (MP4GetTrackTimeScale(mp4File, mediaTrackId) == 90000) { payloadNumber = 14; } MP4SetHintTrackRtpPayload(mp4File, hintTrackId, "MPA", &payloadNumber, 0); u_int16_t bytesThisHint = 0; u_int16_t samplesThisHint = 0; MP4AddRtpHint(mp4File, hintTrackId); MP4AddRtpPacket(mp4File, hintTrackId, true); for (MP4SampleId sampleId = 1; sampleId <= numSamples; sampleId++) { u_int32_t sampleSize = MP4GetSampleSize(mp4File, mediaTrackId, sampleId); if (samplesThisHint > 0) { if (bytesThisHint + sampleSize <= maxPayloadSize) { // add the mp3 frame to current hint MP4AddRtpSampleData(mp4File, hintTrackId, sampleId, 0, sampleSize); samplesThisHint++; bytesThisHint += sampleSize; continue; } else { // write out current hint MP4WriteRtpHint(mp4File, hintTrackId, samplesThisHint * sampleDuration); // start a new hint samplesThisHint = 0; bytesThisHint = 0; MP4AddRtpHint(mp4File, hintTrackId); MP4AddRtpPacket(mp4File, hintTrackId, true); // fall thru } } if (sampleSize + 4 <= maxPayloadSize) { // add rfc 2250 payload header static u_int32_t zero32 = 0; MP4AddRtpImmediateData(mp4File, hintTrackId, (u_int8_t*)&zero32, sizeof(zero32)); // add the mp3 frame to current hint MP4AddRtpSampleData(mp4File, hintTrackId, sampleId, 0, sampleSize); bytesThisHint += (4 + sampleSize); } else { // jumbo frame, need to fragment it u_int16_t sampleOffset = 0; while (sampleOffset < sampleSize) { u_int16_t fragLength = MIN(sampleSize - sampleOffset, maxPayloadSize) - 4; u_int8_t payloadHeader[4]; payloadHeader[0] = payloadHeader[1] = 0; payloadHeader[2] = (sampleOffset >> 8); payloadHeader[3] = sampleOffset & 0xFF; MP4AddRtpImmediateData(mp4File, hintTrackId, (u_int8_t*)&payloadHeader, sizeof(payloadHeader)); MP4AddRtpSampleData(mp4File, hintTrackId, sampleId, sampleOffset, fragLength); sampleOffset += fragLength; // if we're not at the last fragment if (sampleOffset < sampleSize) { MP4AddRtpPacket(mp4File, hintTrackId, false); } } // lie to ourselves so as to force next frame to output // our hint as is, and start a new hint for itself bytesThisHint = maxPayloadSize; } samplesThisHint = 1; } // write out current (final) hint MP4WriteRtpHint(mp4File, hintTrackId, samplesThisHint * sampleDuration); return true; }