examples/alffmpeg.h

   1 #ifndef ALFFMPEG_H
   2 #define ALFFMPEG_H
   3
   4 #ifdef __cplusplus
   5 extern "C" {
   6 #endif /* __cplusplus */
   7
   8 #include <libavcodec/avcodec.h>
   9 #include <libavformat/avformat.h>
  10
  11 /* Opaque handles to files and streams. Apps don't need to concern themselves
  12  * with the internals */
  13 typedef struct MyFile *FilePtr;
  14 typedef struct MyStream *StreamPtr;
  15
  16 /* Opens a file with ffmpeg and sets up the streams' information */
  17 FilePtr openAVFile(const char *fname);
  18
  19 /* Opens a named file image with ffmpeg and sets up the streams' information */
  20 FilePtr openAVData(const char *name, char *buffer, size_t buffer_len);
  21
  22 /* Opens a named data stream with ffmpeg, using the specified data pointer and
  23  * callbacks, and sets up the streams' information */
  24 FilePtr openAVCustom(const char *name, void *user_data,
  25                      int (*read_packet)(void *user_data, uint8_t *buf, int buf_size),
  26                      int (*write_packet)(void *user_data, uint8_t *buf, int buf_size),
  27                      int64_t (*seek)(void *user_data, int64_t offset, int whence));
  28
  29 /* Closes/frees an opened file and any of its streams */
  30 void closeAVFile(FilePtr file);
  31
  32 /* Reports certain information from the file, eg, the number of audio
  33  * streams. Returns 0 on success. */
  34 int getAVFileInfo(FilePtr file, int *numaudiostreams);
  35
  36 /* Retrieves a handle for the given audio stream number (generally 0, but some
  37  * files can have multiple audio streams in one file). */
  38 StreamPtr getAVAudioStream(FilePtr file, int streamnum);
  39
  40 /* Returns information about the given audio stream. Returns 0 on success. */
  41 int getAVAudioInfo(StreamPtr stream, ALuint *rate, ALenum *channels, ALenum *type);
  42
  43 /* Returns a pointer to the next available packet of decoded audio. Any data
  44  * from a previously-decoded packet is dropped. The size (in bytes) of the
  45  * returned data buffer is stored in 'length', and the returned pointer is only
  46  * valid until the next call to getAVAudioData or readAVAudioData. */
  47 void *getAVAudioData(StreamPtr stream, size_t *length);
  48
  49 /* The "meat" function. Decodes audio and writes, at most, length bytes into
  50  * the provided data buffer. Will only return less for end-of-stream or error
  51  * conditions. Returns the number of bytes written. */
  52 size_t readAVAudioData(StreamPtr stream, void *data, size_t length);
  53
  54 /* Decodes all remaining data from the stream and returns a buffer containing
  55  * the audio data, with the size stored in 'length'. The returned pointer must
  56  * be freed with a call to free(). Note that since this decodes the whole
  57  * stream, using it on lengthy streams (eg, music) will use a lot of memory.
  58  * Such streams are better handled using getAVAudioData or readAVAudioData to
  59  * keep smaller chunks in memory at any given time. */
  60 void *decodeAVAudioStream(StreamPtr stream, size_t *length);
  61
  62 #ifdef __cplusplus
  63 }
  64 #endif /* __cplusplus */
  65
  66 #endif /* ALFFMPEG_H */