/* This function creates a magic cookie basec on the codec parameter and formatID
* Return value: a pointer to a magic cookie which has to be av_free()'d
* in cookieSize, the size of the magic cookie is returned to the caller */
uint8_t *create_cookie(AVCodecContext *codec, size_t *cookieSize, UInt32 formatID, int vbr)
{
uint8_t *waveAtom = NULL;
PutByteContext p;
int waveSize;
if (formatID == kAudioFormatMPEG4AAC) {
return CreateEsdsFromSetupData(codec->extradata, codec->extradata_size, cookieSize, 1, true, false);
}
/* Do we need an endia atom, too? */
/* initialize the user Atom
* 8 bytes for the atom size & atom type
* 18 bytes for the already extracted part, see wav.c in the ffmpeg project
* extradata_size for the data still stored in the AVCodecContext structure */
waveSize = 18 + codec->extradata_size + 8;
waveAtom = av_malloc(waveSize);
if (!waveAtom)
goto bail;
bytestream2_init_writer(&p, waveAtom, waveSize);
/* now construct the wave atom */
/* QT Atoms are big endian, I think but the WAVE data should be little endian */
bytestream2_put_be32(&p, waveSize);
bytestream2_put_be32(&p, formatID);
bytestream2_put_le32(&p, codec->codec_tag);
bytestream2_put_le32(&p, codec->channels);
bytestream2_put_le32(&p, codec->sample_rate);
bytestream2_put_le32(&p, vbr ? 0 : codec->bit_rate / 8);
bytestream2_put_le16(&p, codec->block_align);
bytestream2_put_le16(&p, codec->bits_per_coded_sample);
bytestream2_put_le16(&p, codec->extradata_size);
/* now the remaining stuff */
bytestream2_put_buffer(&p, codec->extradata, codec->extradata_size);
bail:
*cookieSize = waveSize;
return waveAtom;
} /* create_cookie() */
static uint8_t* ffat_get_magic_cookie(AVCodecContext *avctx, UInt32 *cookie_size)
{
ATDecodeContext *at = avctx->priv_data;
if (avctx->codec_id == AV_CODEC_ID_AAC) {
char *extradata;
PutByteContext pb;
*cookie_size = 5 + 3 + 5+13 + 5+at->extradata_size;
if (!(extradata = av_malloc(*cookie_size)))
return NULL;
bytestream2_init_writer(&pb, extradata, *cookie_size);
// ES descriptor
put_descr(&pb, 0x03, 3 + 5+13 + 5+at->extradata_size);
bytestream2_put_be16(&pb, 0);
bytestream2_put_byte(&pb, 0x00); // flags (= no flags)
// DecoderConfig descriptor
put_descr(&pb, 0x04, 13 + 5+at->extradata_size);
// Object type indication
bytestream2_put_byte(&pb, 0x40);
bytestream2_put_byte(&pb, 0x15); // flags (= Audiostream)
bytestream2_put_be24(&pb, 0); // Buffersize DB
bytestream2_put_be32(&pb, 0); // maxbitrate
bytestream2_put_be32(&pb, 0); // avgbitrate
// DecoderSpecific info descriptor
put_descr(&pb, 0x05, at->extradata_size);
bytestream2_put_buffer(&pb, at->extradata, at->extradata_size);
return extradata;
} else {
*cookie_size = at->extradata_size;
return at->extradata;
}
}
/* This function creates an image description extension that some codecs need to be able
* to decode properly, a copy of the strf (BITMAPINFOHEADER) chunk in the avi.
* Return value: a handle to an image description extension which has to be DisposeHandle()'d
* in cookieSize, the size of the image description extension is returned to the caller */
Handle create_strf_ext(AVCodecContext *codec)
{
Handle result = NULL;
PutByteContext p;
int size;
/* initialize the extension
* 40 bytes for the BITMAPINFOHEADER stucture, see avienc.c in the ffmpeg project
* extradata_size for the data still stored in the AVCodecContext structure */
size = 40 + codec->extradata_size;
result = NewHandle(size);
if (result == NULL)
goto bail;
bytestream2_init_writer(&p, (uint8_t*)*result, size);
/* construct the BITMAPINFOHEADER structure */
/* QT Atoms are big endian, but the STRF atom should be little endian */
bytestream2_put_be32(&p, size);
bytestream2_put_le32(&p, codec->width);
bytestream2_put_le32(&p, codec->width);
bytestream2_put_le16(&p, 1); // planes
bytestream2_put_le16(&p, codec->bits_per_coded_sample ?: 24);
/* compression type */
bytestream2_put_le32(&p, codec->codec_tag);
bytestream2_put_le32(&p, codec->width * codec->height * 3);
bytestream2_put_le32(&p, 0);
bytestream2_put_le32(&p, 0);
bytestream2_put_le32(&p, 0);
bytestream2_put_le32(&p, 0);
/* now the remaining stuff */
bytestream2_put_buffer(&p, codec->extradata, codec->extradata_size);
if (codec->extradata_size & 1) {
bytestream2_put_byte(&p, 0);
}
bail:
return result;
} /* create_extension() */
