From 71e47640625d1e4db5314a9db0236d82ac267338 Mon Sep 17 00:00:00 2001 From: nu774 Date: Fri, 8 Nov 2013 12:23:52 +0900 Subject: [PATCH] fix to use libFDKAAC signaling mode 1 It turned out that mode 1 is explicit, backward compatible signaling. We don't have to implement it on our side. --- src/aacenc.c | 64 ---------------------------------------------------- src/aacenc.h | 4 ---- src/main.c | 20 ++++------------ 3 files changed, 5 insertions(+), 83 deletions(-) diff --git a/src/aacenc.c b/src/aacenc.c index 44c611a..a6984fe 100644 --- a/src/aacenc.c +++ b/src/aacenc.c @@ -64,70 +64,6 @@ void aacenc_get_lib_info(LIB_INFO *info) free(lib_info); } -static const unsigned aacenc_sampling_freq_tab[] = { - 96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, - 16000, 12000, 11025, 8000, 7350, 0, 0, 0 -}; - -static -unsigned sampling_freq_index(unsigned rate) -{ - unsigned i; - for (i = 0; aacenc_sampling_freq_tab[i]; ++i) - if (aacenc_sampling_freq_tab[i] == rate) - return i; - return 0xf; -} - -/* - * Append backward compatible SBR/PS signaling to implicit signaling ASC, - * if SBR/PS is present. - */ -int aacenc_mp4asc(const aacenc_param_t *params, - const uint8_t *asc, uint32_t ascsize, - uint8_t *outasc, uint32_t *outsize) -{ - unsigned asc_sfreq = aacenc_sampling_freq_tab[(asc[0]&0x7)<<1 |asc[1]>>7]; - unsigned shift = aacenc_is_dual_rate_sbr(params); - - switch (params->profile) { - case AOT_SBR: - case AOT_PS: - if (!shift) - break; - if (*outsize < ascsize + 3) - return -1; - memcpy(outasc, asc, ascsize); - /* syncExtensionType:11 (value:0x2b7) */ - outasc[ascsize+0] = 0x2b << 1; - outasc[ascsize+1] = 0x7 << 5; - /* extensionAudioObjectType:5 (value:5)*/ - outasc[ascsize+1] |= 5; - /* sbrPresentFlag:1 (value:1) */ - outasc[ascsize+2] = 0x80; - /* extensionSamplingFrequencyIndex:4 */ - outasc[ascsize+2] |= sampling_freq_index(asc_sfreq << shift) << 3; - if (params->profile == AOT_SBR) { - *outsize = ascsize + 3; - return 0; - } - if (*outsize < ascsize + 5) - return -1; - /* syncExtensionType:11 (value:0x548) */ - outasc[ascsize+2] |= 0x5; - outasc[ascsize+3] = 0x48; - /* psPresentFlag:1 (value:1) */ - outasc[ascsize+4] = 0x80; - *outsize = ascsize + 5; - return 0; - } - if (*outsize < ascsize) - return -1; - memcpy(outasc, asc, ascsize); - *outsize = ascsize; - return 0; -} - static int aacenc_channel_mode(const pcm_sample_description_t *format) { diff --git a/src/aacenc.h b/src/aacenc.h index 368a440..ec0bea1 100644 --- a/src/aacenc.h +++ b/src/aacenc.h @@ -38,10 +38,6 @@ int aacenc_is_dual_rate_sbr(const aacenc_param_t *params); void aacenc_get_lib_info(LIB_INFO *info); -int aacenc_mp4asc(const aacenc_param_t *params, - const uint8_t *asc, uint32_t ascsize, - uint8_t *outasc, uint32_t *outsize); - int aacenc_init(HANDLE_AACENCODER *encoder, const aacenc_param_t *params, const pcm_sample_description_t *format, AACENC_InfoStruct *info); diff --git a/src/main.c b/src/main.c index 9e89488..ef2fa87 100644 --- a/src/main.c +++ b/src/main.c @@ -785,15 +785,6 @@ int main(int argc, char **argv) sample_format = pcm_get_format(reader); - /* - * We use explicit/hierarchical signaling for LOAS. - * Other than that, we request implicit signaling to FDK library, then - * append explicit/backward-compatible signaling to ASC in case of MP4FF. - * - * Explicit/backward-compatible signaling of SBR is the most recommended - * way in MPEG4 part3 spec, and seems the only way supported by iTunes. - * Since FDK library does not support it, we have to do it on our side. - */ sbr_mode = aacenc_is_sbr_active((aacenc_param_t*)¶ms); if (sbr_mode && !aacenc_is_sbr_ratio_available()) { fprintf(stderr, "WARNING: Only dual-rate SBR is available " @@ -801,7 +792,9 @@ int main(int argc, char **argv) params.sbr_ratio = 2; } scale_shift = aacenc_is_dual_rate_sbr((aacenc_param_t*)¶ms); - params.sbr_signaling = (params.transport_format == TT_MP4_LOAS) ? 2 : 0; + params.sbr_signaling = + (params.transport_format == TT_MP4_LOAS) ? 2 : + (params.transport_format == TT_MP4_RAW) ? 1 : 0; if (sbr_mode && !scale_shift) params.sbr_signaling = 2; @@ -824,16 +817,13 @@ int main(int argc, char **argv) if (!params.transport_format) { uint32_t scale; - uint8_t mp4asc[32]; - uint32_t ascsize = sizeof(mp4asc); unsigned framelen = aacinfo.frameLength; scale = sample_format->sample_rate >> scale_shift; if ((m4af = m4af_create(M4AF_CODEC_MP4A, scale, &m4af_io, params.output_fp)) < 0) goto END; - aacenc_mp4asc((aacenc_param_t*)¶ms, aacinfo.confBuf, - aacinfo.confSize, mp4asc, &ascsize); - m4af_set_decoder_specific_info(m4af, 0, mp4asc, ascsize); + m4af_set_decoder_specific_info(m4af, 0, + aacinfo.confBuf, aacinfo.confSize); m4af_set_fixed_frame_duration(m4af, 0, framelen >> scale_shift); m4af_set_vbr_mode(m4af, 0, params.bitrate_mode); -- 2.30.2