[FFmpeg-devel] [PATCH v2 2/4] avcodec/mlpdec: add detection of Atmos spatial extension profile in TrueHD
Hendrik Leppkes
h.leppkes at gmail.com
Sat Feb 18 18:50:11 EET 2023
On Sat, Feb 18, 2023 at 2:15 AM Marth64 <marth64 at proxyid.net> wrote:
>
> Signed-off-by: Marth64 <marth64 at proxyid.net>
> ---
> libavcodec/avcodec.h | 2 ++
> libavcodec/codec_desc.c | 1 +
> libavcodec/mlpdec.c | 11 +++++++++++
> libavcodec/profiles.c | 5 +++++
> libavcodec/profiles.h | 1 +
> 5 files changed, 20 insertions(+)
>
> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> index 0e85dd50a4..3feab75741 100644
> --- a/libavcodec/avcodec.h
> +++ b/libavcodec/avcodec.h
> @@ -1593,6 +1593,8 @@ typedef struct AVCodecContext {
>
> #define FF_PROFILE_EAC3_DDP_ATMOS 30
>
> +#define FF_PROFILE_TRUEHD_ATMOS 30
> +
> #define FF_PROFILE_MPEG2_422 0
> #define FF_PROFILE_MPEG2_HIGH 1
> #define FF_PROFILE_MPEG2_SS 2
> diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
> index 4098d4f5a5..e80ac07700 100644
> --- a/libavcodec/codec_desc.c
> +++ b/libavcodec/codec_desc.c
> @@ -2960,6 +2960,7 @@ static const AVCodecDescriptor codec_descriptors[] = {
> .name = "truehd",
> .long_name = NULL_IF_CONFIG_SMALL("TrueHD"),
> .props = AV_CODEC_PROP_LOSSLESS,
> + .profiles = NULL_IF_CONFIG_SMALL(ff_truehd_profiles),
> },
> {
> .id = AV_CODEC_ID_MP4ALS,
> diff --git a/libavcodec/mlpdec.c b/libavcodec/mlpdec.c
> index 0ee1f0982c..85d6207b9c 100644
> --- a/libavcodec/mlpdec.c
> +++ b/libavcodec/mlpdec.c
> @@ -42,6 +42,7 @@
> #include "mlpdsp.h"
> #include "mlp.h"
> #include "config.h"
> +#include "profiles.h"
>
> /** number of bits used for VLC lookup - longest Huffman code is 9 */
> #if ARCH_ARM
> @@ -392,6 +393,15 @@ static int read_major_sync(MLPDecodeContext *m, GetBitContext *gb)
> m->num_substreams = mh.num_substreams;
> m->substream_info = mh.substream_info;
>
> + /* If there is a 4th substream and the MSB of substream_info is set,
> + * there is a 16-channel spatial presentation (Atmos in TrueHD).
> + */
> + if (m->avctx->codec_id == AV_CODEC_ID_TRUEHD
> + && m->num_substreams == 4
> + && m->substream_info >> 7 == 1) {
> + m->avctx->profile = FF_PROFILE_TRUEHD_ATMOS;
> + }
> +
Nit: maybe put the if into two lines instead of three? The two
substream checks look like they should fit in one line quite well. But
this is just a style question, so feel free to ignore.
Otherwise LGTM
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