diff options
Diffstat (limited to 'media/libstagefright/avc_utils.cpp')
-rw-r--r-- | media/libstagefright/avc_utils.cpp | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/media/libstagefright/avc_utils.cpp b/media/libstagefright/avc_utils.cpp index 8762d29..478e40c 100644 --- a/media/libstagefright/avc_utils.cpp +++ b/media/libstagefright/avc_utils.cpp @@ -18,6 +18,9 @@ #include <media/stagefright/foundation/ABitReader.h> #include <media/stagefright/foundation/ADebug.h> +#include <media/stagefright/MediaDefs.h> +#include <media/stagefright/MediaErrors.h> +#include <media/stagefright/MetaData.h> namespace android { @@ -124,5 +127,176 @@ void FindAVCDimensions( } } +status_t getNextNALUnit( + const uint8_t **_data, size_t *_size, + const uint8_t **nalStart, size_t *nalSize, + bool startCodeFollows) { + const uint8_t *data = *_data; + size_t size = *_size; + + *nalStart = NULL; + *nalSize = 0; + + if (size == 0) { + return -EAGAIN; + } + + // Skip any number of leading 0x00. + + size_t offset = 0; + while (offset < size && data[offset] == 0x00) { + ++offset; + } + + if (offset == size) { + return -EAGAIN; + } + + // A valid startcode consists of at least two 0x00 bytes followed by 0x01. + + if (offset < 2 || data[offset] != 0x01) { + return ERROR_MALFORMED; + } + + ++offset; + + size_t startOffset = offset; + + for (;;) { + while (offset < size && data[offset] != 0x01) { + ++offset; + } + + if (offset == size) { + if (startCodeFollows) { + offset = size + 2; + break; + } + + return -EAGAIN; + } + + if (data[offset - 1] == 0x00 && data[offset - 2] == 0x00) { + break; + } + + ++offset; + } + + size_t endOffset = offset - 2; + while (data[endOffset - 1] == 0x00) { + --endOffset; + } + + *nalStart = &data[startOffset]; + *nalSize = endOffset - startOffset; + + if (offset + 2 < size) { + *_data = &data[offset - 2]; + *_size = size - offset + 2; + } else { + *_data = NULL; + *_size = 0; + } + + return OK; +} + +static sp<ABuffer> FindNAL( + const uint8_t *data, size_t size, unsigned nalType, + size_t *stopOffset) { + const uint8_t *nalStart; + size_t nalSize; + while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) { + if ((nalStart[0] & 0x1f) == nalType) { + sp<ABuffer> buffer = new ABuffer(nalSize); + memcpy(buffer->data(), nalStart, nalSize); + return buffer; + } + } + + return NULL; +} + +sp<MetaData> MakeAVCCodecSpecificData(const sp<ABuffer> &accessUnit) { + const uint8_t *data = accessUnit->data(); + size_t size = accessUnit->size(); + + sp<ABuffer> seqParamSet = FindNAL(data, size, 7, NULL); + if (seqParamSet == NULL) { + return NULL; + } + + int32_t width, height; + FindAVCDimensions(seqParamSet, &width, &height); + + size_t stopOffset; + sp<ABuffer> picParamSet = FindNAL(data, size, 8, &stopOffset); + CHECK(picParamSet != NULL); + + size_t csdSize = + 1 + 3 + 1 + 1 + + 2 * 1 + seqParamSet->size() + + 1 + 2 * 1 + picParamSet->size(); + + sp<ABuffer> csd = new ABuffer(csdSize); + uint8_t *out = csd->data(); + + *out++ = 0x01; // configurationVersion + memcpy(out, seqParamSet->data() + 1, 3); // profile/level... + out += 3; + *out++ = (0x3f << 2) | 1; // lengthSize == 2 bytes + *out++ = 0xe0 | 1; + + *out++ = seqParamSet->size() >> 8; + *out++ = seqParamSet->size() & 0xff; + memcpy(out, seqParamSet->data(), seqParamSet->size()); + out += seqParamSet->size(); + + *out++ = 1; + + *out++ = picParamSet->size() >> 8; + *out++ = picParamSet->size() & 0xff; + memcpy(out, picParamSet->data(), picParamSet->size()); + +#if 0 + LOGI("AVC seq param set"); + hexdump(seqParamSet->data(), seqParamSet->size()); +#endif + + sp<MetaData> meta = new MetaData; + meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_VIDEO_AVC); + + meta->setData(kKeyAVCC, 0, csd->data(), csd->size()); + meta->setInt32(kKeyWidth, width); + meta->setInt32(kKeyHeight, height); + + LOGI("found AVC codec config (%d x %d)", width, height); + + return meta; +} + +bool IsIDR(const sp<ABuffer> &buffer) { + const uint8_t *data = buffer->data(); + size_t size = buffer->size(); + + bool foundIDR = false; + + const uint8_t *nalStart; + size_t nalSize; + while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) { + CHECK_GT(nalSize, 0u); + + unsigned nalType = nalStart[0] & 0x1f; + + if (nalType == 5) { + foundIDR = true; + break; + } + } + + return foundIDR; +} + } // namespace android |