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Diffstat (limited to 'media/libstagefright/rtsp/ASessionDescription.cpp')
| -rw-r--r-- | media/libstagefright/rtsp/ASessionDescription.cpp | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/media/libstagefright/rtsp/ASessionDescription.cpp b/media/libstagefright/rtsp/ASessionDescription.cpp new file mode 100644 index 0000000..a9b3330 --- /dev/null +++ b/media/libstagefright/rtsp/ASessionDescription.cpp @@ -0,0 +1,336 @@ +/* + * Copyright (C) 2010 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +//#define LOG_NDEBUG 0 +#define LOG_TAG "ASessionDescription" +#include <utils/Log.h> + +#include "ASessionDescription.h" + +#include <media/stagefright/foundation/ADebug.h> +#include <media/stagefright/foundation/AString.h> + +#include <stdlib.h> + +namespace android { + +ASessionDescription::ASessionDescription() + : mIsValid(false) { +} + +ASessionDescription::~ASessionDescription() { +} + +bool ASessionDescription::setTo(const void *data, size_t size) { + mIsValid = parse(data, size); + + if (!mIsValid) { + mTracks.clear(); + mFormats.clear(); + } + + return mIsValid; +} + +bool ASessionDescription::parse(const void *data, size_t size) { + mTracks.clear(); + mFormats.clear(); + + mTracks.push(Attribs()); + mFormats.push(AString("[root]")); + + AString desc((const char *)data, size); + + size_t i = 0; + for (;;) { + ssize_t eolPos = desc.find("\n", i); + + if (eolPos < 0) { + break; + } + + AString line; + if ((size_t)eolPos > i && desc.c_str()[eolPos - 1] == '\r') { + // We accept both '\n' and '\r\n' line endings, if it's + // the latter, strip the '\r' as well. + line.setTo(desc, i, eolPos - i - 1); + } else { + line.setTo(desc, i, eolPos - i); + } + + if (line.empty()) { + i = eolPos + 1; + continue; + } + + if (line.size() < 2 || line.c_str()[1] != '=') { + return false; + } + + ALOGI("%s", line.c_str()); + + switch (line.c_str()[0]) { + case 'v': + { + if (strcmp(line.c_str(), "v=0")) { + return false; + } + break; + } + + case 'a': + case 'b': + { + AString key, value; + + ssize_t colonPos = line.find(":", 2); + if (colonPos < 0) { + key = line; + } else { + key.setTo(line, 0, colonPos); + + if (key == "a=fmtp" || key == "a=rtpmap" + || key == "a=framesize") { + ssize_t spacePos = line.find(" ", colonPos + 1); + if (spacePos < 0) { + return false; + } + + key.setTo(line, 0, spacePos); + + colonPos = spacePos; + } + + value.setTo(line, colonPos + 1, line.size() - colonPos - 1); + } + + key.trim(); + value.trim(); + + ALOGV("adding '%s' => '%s'", key.c_str(), value.c_str()); + + mTracks.editItemAt(mTracks.size() - 1).add(key, value); + break; + } + + case 'm': + { + ALOGV("new section '%s'", + AString(line, 2, line.size() - 2).c_str()); + + mTracks.push(Attribs()); + mFormats.push(AString(line, 2, line.size() - 2)); + break; + } + + default: + { + AString key, value; + + ssize_t equalPos = line.find("="); + + key = AString(line, 0, equalPos + 1); + value = AString(line, equalPos + 1, line.size() - equalPos - 1); + + key.trim(); + value.trim(); + + ALOGV("adding '%s' => '%s'", key.c_str(), value.c_str()); + + mTracks.editItemAt(mTracks.size() - 1).add(key, value); + break; + } + } + + i = eolPos + 1; + } + + return true; +} + +bool ASessionDescription::isValid() const { + return mIsValid; +} + +size_t ASessionDescription::countTracks() const { + return mTracks.size(); +} + +void ASessionDescription::getFormat(size_t index, AString *value) const { + CHECK_GE(index, 0u); + CHECK_LT(index, mTracks.size()); + + *value = mFormats.itemAt(index); +} + +bool ASessionDescription::findAttribute( + size_t index, const char *key, AString *value) const { + CHECK_GE(index, 0u); + CHECK_LT(index, mTracks.size()); + + value->clear(); + + const Attribs &track = mTracks.itemAt(index); + ssize_t i = track.indexOfKey(AString(key)); + + if (i < 0) { + return false; + } + + *value = track.valueAt(i); + + return true; +} + +void ASessionDescription::getFormatType( + size_t index, unsigned long *PT, + AString *desc, AString *params) const { + AString format; + getFormat(index, &format); + + const char *lastSpacePos = strrchr(format.c_str(), ' '); + CHECK(lastSpacePos != NULL); + + char *end; + unsigned long x = strtoul(lastSpacePos + 1, &end, 10); + CHECK_GT(end, lastSpacePos + 1); + CHECK_EQ(*end, '\0'); + + *PT = x; + + char key[20]; + sprintf(key, "a=rtpmap:%lu", x); + + CHECK(findAttribute(index, key, desc)); + + sprintf(key, "a=fmtp:%lu", x); + if (!findAttribute(index, key, params)) { + params->clear(); + } +} + +bool ASessionDescription::getDimensions( + size_t index, unsigned long PT, + int32_t *width, int32_t *height) const { + *width = 0; + *height = 0; + + char key[20]; + sprintf(key, "a=framesize:%lu", PT); + AString value; + if (!findAttribute(index, key, &value)) { + return false; + } + + const char *s = value.c_str(); + char *end; + *width = strtoul(s, &end, 10); + CHECK_GT(end, s); + CHECK_EQ(*end, '-'); + + s = end + 1; + *height = strtoul(s, &end, 10); + CHECK_GT(end, s); + CHECK_EQ(*end, '\0'); + + return true; +} + +bool ASessionDescription::getDurationUs(int64_t *durationUs) const { + *durationUs = 0; + + CHECK(mIsValid); + + AString value; + if (!findAttribute(0, "a=range", &value)) { + return false; + } + + if (strncmp(value.c_str(), "npt=", 4)) { + return false; + } + + float from, to; + if (!parseNTPRange(value.c_str() + 4, &from, &to)) { + return false; + } + + *durationUs = (int64_t)((to - from) * 1E6); + + return true; +} + +// static +void ASessionDescription::ParseFormatDesc( + const char *desc, int32_t *timescale, int32_t *numChannels) { + const char *slash1 = strchr(desc, '/'); + CHECK(slash1 != NULL); + + const char *s = slash1 + 1; + char *end; + unsigned long x = strtoul(s, &end, 10); + CHECK_GT(end, s); + CHECK(*end == '\0' || *end == '/'); + + *timescale = x; + *numChannels = 1; + + if (*end == '/') { + s = end + 1; + unsigned long x = strtoul(s, &end, 10); + CHECK_GT(end, s); + CHECK_EQ(*end, '\0'); + + *numChannels = x; + } +} + +// static +bool ASessionDescription::parseNTPRange( + const char *s, float *npt1, float *npt2) { + if (s[0] == '-') { + return false; // no start time available. + } + + if (!strncmp("now", s, 3)) { + return false; // no absolute start time available + } + + char *end; + *npt1 = strtof(s, &end); + + if (end == s || *end != '-') { + // Failed to parse float or trailing "dash". + return false; + } + + s = end + 1; // skip the dash. + + if (!strncmp("now", s, 3)) { + return false; // no absolute end time available + } + + *npt2 = strtof(s, &end); + + if (end == s || *end != '\0') { + return false; + } + + return *npt2 > *npt1; +} + +} // namespace android + |