[FFmpeg-devel] [PATCH 2/3] Add single stream LATM/LOAS decoder
Michael Niedermayer
michaelni
Tue Oct 19 10:11:22 CEST 2010
On Mon, Oct 18, 2010 at 07:37:14PM +0200, Janne Grunau wrote:
> The decoder is basicly just a wrapper around the AAC decoder.
> based on patch by Paul Kendall { paul <?t> kcbbs gen nz }
> ---
> Changelog | 1 +
> configure | 1 +
> libavcodec/Makefile | 2 +
> libavcodec/aacdec.c | 9 +-
> libavcodec/aacdec.h | 3 +
> libavcodec/aaclatmdec.c | 419 ++++++++++++++++++++++++++++++++++++++++++++++
> libavcodec/allcodecs.c | 2 +
> libavcodec/avcodec.h | 3 +-
> libavcodec/latm_parser.c | 119 +++++++++++++
> 9 files changed, 553 insertions(+), 6 deletions(-)
> create mode 100644 libavcodec/aaclatmdec.c
> create mode 100644 libavcodec/latm_parser.c
>
> diff --git a/Changelog b/Changelog
> index 426a92d..b6ada6b 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -47,6 +47,7 @@ version <next>:
> - SAP (Session Announcement Protocol, RFC 2974) muxer and demuxer
> - cropdetect filter
> - ffmpeg -crop* options removed
> +- single stream LATM/LOAS decoder
>
>
> version 0.6:
> diff --git a/configure b/configure
> index 0e6e439..f3e65d4 100755
> --- a/configure
> +++ b/configure
> @@ -1187,6 +1187,7 @@ rdft_select="fft"
> # decoders / encoders / hardware accelerators
> aac_decoder_select="mdct rdft"
> aac_encoder_select="mdct"
> +aac_latm_decoder_select="aac_decoder"
> ac3_decoder_select="mdct ac3_parser"
> alac_encoder_select="lpc"
> amrnb_decoder_select="lsp"
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 385ae02..bd5f041 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -52,6 +52,7 @@ OBJS-$(CONFIG_AAC_ENCODER) += aacenc.o aaccoder.o \
> aacpsy.o aactab.o \
> psymodel.o iirfilter.o \
> mpeg4audio.o
> +OBJS-$(CONFIG_AAC_LATM_DECODER) += aaclatmdec.o
> OBJS-$(CONFIG_AASC_DECODER) += aasc.o msrledec.o
> OBJS-$(CONFIG_AC3_DECODER) += ac3dec.o ac3dec_data.o ac3.o
> OBJS-$(CONFIG_AC3_ENCODER) += ac3enc.o ac3tab.o ac3.o
> @@ -576,6 +577,7 @@ OBJS-$(CONFIG_H264_PARSER) += h264_parser.o h264.o \
> h264_loopfilter.o h264_cabac.o \
> h264_cavlc.o h264_ps.o \
> mpegvideo.o error_resilience.o
> +OBJS-$(CONFIG_AAC_LATM_PARSER) += latm_parser.o
> OBJS-$(CONFIG_MJPEG_PARSER) += mjpeg_parser.o
> OBJS-$(CONFIG_MLP_PARSER) += mlp_parser.o mlp.o
> OBJS-$(CONFIG_MPEG4VIDEO_PARSER) += mpeg4video_parser.o h263.o \
> diff --git a/libavcodec/aacdec.c b/libavcodec/aacdec.c
> index 4306483..b2cf7b2 100644
> --- a/libavcodec/aacdec.c
> +++ b/libavcodec/aacdec.c
> @@ -516,7 +516,7 @@ static void reset_predictor_group(PredictorState *ps, int group_num)
> ff_aac_spectral_codes[num], sizeof(ff_aac_spectral_codes[num][0]), sizeof(ff_aac_spectral_codes[num][0]), \
> size);
>
> -static av_cold int aac_decode_init(AVCodecContext *avctx)
> +av_cold int ff_aac_decode_init(AVCodecContext *avctx)
> {
> AACContext *ac = avctx->priv_data;
>
> @@ -2068,8 +2068,7 @@ static int aac_decode_frame(AVCodecContext *avctx, void *data,
>
> return buf_size > buf_offset ? buf_consumed : buf_size;
> }
> -
> -static av_cold int aac_decode_close(AVCodecContext *avctx)
> +av_cold int ff_aac_decode_close(AVCodecContext *avctx)
> {
> AACContext *ac = avctx->priv_data;
> int i, type;
> @@ -2092,9 +2091,9 @@ AVCodec aac_decoder = {
> AVMEDIA_TYPE_AUDIO,
> CODEC_ID_AAC,
> sizeof(AACContext),
> - aac_decode_init,
> + ff_aac_decode_init,
> NULL,
> - aac_decode_close,
> + ff_aac_decode_close,
> aac_decode_frame,
> .long_name = NULL_IF_CONFIG_SMALL("Advanced Audio Coding"),
> .sample_fmts = (const enum SampleFormat[]) {
> diff --git a/libavcodec/aacdec.h b/libavcodec/aacdec.h
> index a16bfa0..fa1f1d0 100644
> --- a/libavcodec/aacdec.h
> +++ b/libavcodec/aacdec.h
> @@ -28,6 +28,9 @@
> #include "avcodec.h"
> #include "get_bits.h"
>
> +av_cold int ff_aac_decode_init(AVCodecContext *avctx);
> +
> +av_cold int ff_aac_decode_close(AVCodecContext *avctx);
>
> int ff_aac_decode_frame_int(AVCodecContext *avctx, void *data,
> int *data_size, GetBitContext *gb);
does that av_cold in there have any effect?
[...]
> +struct LATMContext {
> + AACContext aac_ctx;
> + int initialized; // initilized after a valid extradata is set
> +
> + // parser data
> + int audio_mux_version_A; // LATM syntax version
> + int frame_length_type; // 0/1 variable/fixed frame length
> + int frame_length; // frame length for fixed frame length
doxy
> +};
> +
> +static inline uint32_t latm_get_value(GetBitContext *b)
> +{
> + int length = get_bits(b, 2);
> + uint32_t value = 0;
> + int i;
> + for (i = 0; i <= length; i++) {
> + value <<= 8;
> + value |= get_bits(b, 8);
> + }
> + return value;
isnt this
return get_bits_long((length+1)*8);
?
> +}
> +
> +//copied from ff_copy_pce_data() in mpeg4audio.c
> +static int parse_pce_data(GetBitContext *gb)
> +{
> + int five_bit_ch, four_bit_ch, comment_size, bits;
> + int offset = get_bits_count(gb);
> +
> + skip_bits(gb, 10); //Tag, Object Type, Frequency
> + five_bit_ch = get_bits(gb, 4); //Front
> + five_bit_ch += get_bits(gb, 4); //Side
> + five_bit_ch += get_bits(gb, 4); //Back
> + four_bit_ch = get_bits(gb, 2); //LFE
> + four_bit_ch += get_bits(gb, 3); //Data
> + five_bit_ch += get_bits(gb, 4); //Coupling
> + if (get_bits(gb, 1)) //Mono Mixdown
> + skip_bits(gb, 4);
> + if (get_bits(gb, 1)) //Stereo Mixdown
> + skip_bits(gb, 4);
> + if (get_bits(gb, 1)) //Matrix Mixdown
> + skip_bits(gb, 3);
> + for (bits = five_bit_ch*5+four_bit_ch*4; bits > 16; bits -= 16)
> + skip_bits(gb, 16);
> + if (bits)
> + skip_bits(gb, bits);
skip_bits_long() ?
> + align_get_bits(gb);
> + comment_size = get_bits(gb, 8);
> + for (; comment_size > 0; comment_size--)
> + get_bits(gb, 8);
same
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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