mp4v2库 libmp4v2.dll

#ifndef MP4V2_SAMPLE_H #define MP4V2_SAMPLE_H /**************************************************************************//** * * @defgroup mp4_sample MP4v2 Sample * @{ * *****************************************************************************/ /** Sample dependency types. * * Bit combinations 0x03, 0x30, 0xc0 are reserved. */ typedef enum MP4SampleDependencyType_e { MP4_SDT_UNKNOWN = 0x00, /**< unknown */ MP4_SDT_HAS_REDUNDANT_CODING = 0x01, /**< contains redundant coding */ MP4_SDT_HAS_NO_REDUNDANT_CODING = 0x02, /**< does not contain redundant coding */ MP4_SDT_HAS_DEPENDENTS = 0x04, /**< referenced by other samples */ MP4_SDT_HAS_NO_DEPENDENTS = 0x08, /**< not referenced by other samples */ MP4_SDT_IS_DEPENDENT = 0x10, /**< references other samples */ MP4_SDT_IS_INDEPENDENT = 0x20, /**< does not reference other samples */ MP4_SDT_EARLIER_DISPLAY_TIMES_ALLOWED = 0x40, /**< subequent samples in GOP may display earlier */ _MP4_SDT_RESERVED = 0x80 /**< reserved */ } MP4SampleDependencyType; /** Read a track sample. * * MP4ReadSample reads the specified sample from the specified track. * Typically this sample is then decoded in a codec dependent fashion and * rendered in an appropriate fashion. * * The argument <b>ppBytes</b> allows for two possible approaches for * buffering: * * If the calling application wishes to handle its own buffering it can set * *ppBytes to the buffer it wishes to use. The calling application is * responsible for ensuring that the buffer is large enough to hold the * sample. This can be done by using either MP4GetSampleSize() or * MP4GetTrackMaxSampleSize() to determine before-hand how large the * receiving buffer must be. * * If the value of *ppBytes is NULL, then an appropriately sized buffer is * automatically malloc'ed for the sample data and *ppBytes set to this * pointer. The calling application is responsible for free'ing this * memory. * * The last four arguments are pointers to variables that can receive * optional sample information. * * Typically for audio none of these are needed. MPEG audio such as MP3 or * AAC has a fixed sample duration and every sample can be accessed at * random. * * For video, all of these optional values could be needed. MPEG video can * be encoded at a variable frame rate, with only occasional random access * points, and with "B frames" which cause the rendering (display) order * of the video frames to differ from the storage/decoding order. * * Other media types fall between these two extremes. * * @param hFile handle of file for operation. * @param trackId id of track for operation. * @param sampleId specifies which sample is to be read. * Caveat: the first sample has id <b>1</b> not <b>0</b>. * @param ppBytes pointer to the pointer to the sample data. * @param pNumBytes pointer to variable that will be hold the size in bytes * of the sample. * @param pStartTime if non-NULL, pointer to variable that will receive the * starting timestamp for this sample. Caveat: The timestamp is in * <b>trackId</b>'s timescale. * @param pDuration if non-NULL, pointer to variable that will receive the * duration for this sample. Caveat: The duration is in * <b>trackId</b>'s timescale. * @param pRenderingOffset if non-NULL, pointer to variable that will * receive the rendering offset for this sample. Currently the only * media type that needs this feature is MPEG video. Caveat: The offset * is in <b>trackId</b>'s timescale. * @param pIsSyncSample if non-NULL, pointer to variable that will receive * the state of the sync/random access flag for this sample. * * @return <b>true</b> on success, <b>false</b> on failure. * * @see MP4GetSampleSize(). * @see MP4GetTrackMaxSampleSize(). */ MP4V2_EXPORT bool MP4ReadSample( /* input parameters */ MP4FileHandle hFile, MP4TrackId trackId, MP4SampleId sampleId, /* input/output parameters */ uint8_t** ppBytes, uint32_t* pNumBytes, /* output parameters */ MP4Timestamp* pStartTime DEFAULT(NULL), MP4Duration* pDuration DEFAULT(NULL), MP4Duration* pRenderingOffset DEFAULT(NULL), bool* pIsSyncSample DEFAULT(NULL) ); /** Read a track sample based on a specified time. * * MP4ReadSampleFromTime is similar to MP4ReadSample() except the sample * is specified by using a timestamp instead of sampleId. * Typically this sample is then decoded in a codec dependent fashion and * rendered in an appropriate fashion. * * The argument <b>ppBytes</b> allows for two possible approaches for * buffering: * * If the calling application wishes to handle its own buffering it can set * *ppBytes to the buffer it wishes to use. The calling application is * responsible for ensuring that the buffer is large enough to hold the * sample. This can be done by using either MP4GetSampleSize() or * MP4GetTrackMaxSampleSize() to determine before-hand how large the * receiving buffer must be. * * If the value of *ppBytes is NULL, then an appropriately sized buffer is * automatically malloc'ed for the sample data and *ppBytes set to this * pointer. The calling application is responsible for free'ing this * memory. * * The last four arguments are pointers to variables that can receive * optional sample information. * * Typically for audio none of these are needed. MPEG audio such as MP3 or * AAC has a fixed sample duration and every sample can be accessed at * random. * * For video, all of these optional values could be needed. MPEG video can * be encoded at a variable frame rate, with only occasional random access * points, and with "B frames" which cause the rendering (display) order * of the video frames to differ from the storage/decoding order. * * Other media types fall between these two extremes. * * @param hFile handle of file for operation. * @param trackId id of track for operation. * @param when specifies which sample is to be read based on a time in the * track timeline. See MP4GetSampleIdFromTime() for details. * @param ppBytes pointer to the pointer to the sample data. * @param pNumBytes pointer to variable that will be hold the size in bytes * of the sample. * @param pStartTime if non-NULL, pointer to variable that will receive the * starting timestamp for this sample. Caveat: The timestamp is in * <b>trackId</b>'s timescale. * @param pDuration if non-NULL, pointer to variable that will receive the * duration for this sample. Caveat: The duration is in * <b>trackId</b>'s timescale. * @param pRenderingOffset if non-NULL, pointer to variable that will * receive the rendering offset for this sample. Currently the only * media type that needs this feature is MPEG video. Caveat: The offset * is in <b>trackId</b>'s timescale. * @param pIsSyncSample if non-NULL, pointer to variable that will receive * the state of the sync/random access flag for this sample. * * @return <b>true</b> on success, <b>false</b> on failure. * * @see MP4ReadSample(). * @see MP4GetSampleIdFromTime(). * @see MP4GetSampleSize(). * @see MP4GetTrackMaxSampleSize(). */ MP4V2_EXPORT bool MP4ReadSampleFromTime( /* input parameters */ MP4FileHandle hFile, MP4TrackId trackId, MP4Timestamp when, /* input/output parameters */ uint8_t** ppBytes, uint32_t* pNumBytes, /* output parameters */ MP4Timestamp* pStartTime DEFAULT(NULL), MP4Duration* pDuration DEFAULT(NULL), MP4Duration* pRenderingOffs