On 06/13/2011 05:23 AM, Anton Khirnov wrote:
> From: Carl Eugen Hoyos <[email protected]>
>
> TrueHD supports more channels than FFmpeg, so a valid sample
> could set the channel layout to a value that represents less
> channels than the sample actually consists of.
>
> Signed-off-by: Anton Khirnov <[email protected]>
> ---
> libavcodec/mlp_parser.c | 4 ++++
> 1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/libavcodec/mlp_parser.c b/libavcodec/mlp_parser.c
> index e85eb72..7f694d9 100644
> --- a/libavcodec/mlp_parser.c
> +++ b/libavcodec/mlp_parser.c
> @@ -326,6 +326,10 @@ static int mlp_parse(AVCodecParserContext *s,
> avctx->channels = truehd_channels(mh.channels_thd_stream1);
> avctx->channel_layout =
> truehd_layout(mh.channels_thd_stream1);
> }
> + if (av_get_channel_layout_nb_channels(avctx->channel_layout) !=
> avctx->channels) {
> + avctx->channel_layout = 0;
> + av_log_ask_for_sample(avctx, "Unknown channel layout.");
> + }
> }
>
> if (!mh.is_vbr) /* Stream is CBR */
This doesn't make sense. If there are channels in TrueHD that aren't
"supported" (i.e. defined) then we should just define them. It looks
like currently SIDE_LEFT and SIDE_RIGHT are duplicated twice, but all
the other channels are unique.
static const uint64_t thd_layout[13] = {
...
AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRs
...
AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRc
...
AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRsd
};
It looks like we need:
Left center
Right center
Left surround direct
Right surround direct
Like attached.
-Justin
>From 606323317b6791fb7965d9747578b4226be458f7 Mon Sep 17 00:00:00 2001
From: Justin Ruggles <[email protected]>
Date: Mon, 13 Jun 2011 08:38:18 -0400
Subject: [PATCH] Add new channel layouts and use them in the MLP/TrueHD parser.
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="------------1.7.1"
This is a multi-part message in MIME format.
--------------1.7.1
Content-Type: text/plain; charset=UTF-8; format=fixed
Content-Transfer-Encoding: 8bit
---
libavcodec/mlp_parser.c | 7 ++++---
libavutil/audioconvert.h | 4 ++++
2 files changed, 8 insertions(+), 3 deletions(-)
--------------1.7.1
Content-Type: text/x-patch; name="0001-Add-new-channel-layouts-and-use-them-in-the-MLP-True.patch"
Content-Transfer-Encoding: 8bit
Content-Disposition: attachment; filename="0001-Add-new-channel-layouts-and-use-them-in-the-MLP-True.patch"
diff --git a/libavcodec/mlp_parser.c b/libavcodec/mlp_parser.c
index e85eb72..5a77865 100644
--- a/libavcodec/mlp_parser.c
+++ b/libavcodec/mlp_parser.c
@@ -79,11 +79,11 @@ static const uint64_t thd_layout[13] = {
AV_CH_LOW_FREQUENCY, // LFE
AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRs
AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT, // LRvh
- AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRc
+ AV_CH_LEFT_CENTER|AV_CH_RIGHT_CENTER, // LRc
AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT, // LRrs
AV_CH_BACK_CENTER, // Cs
AV_CH_TOP_BACK_CENTER, // Ts
- AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRsd
+ AV_CH_LEFT_SURROUND_DIRECT|AV_CH_RIGHT_SURROUND_DIRECT, // LRsd
AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER, // LRw
AV_CH_TOP_BACK_CENTER, // Cvh
AV_CH_LOW_FREQUENCY // LFE2
@@ -109,7 +109,8 @@ static int truehd_channels(int chanmap)
static int64_t truehd_layout(int chanmap)
{
- int layout = 0, i;
+ int i;
+ int64_t layout = 0;
for (i = 0; i < 13; i++)
layout |= thd_layout[i] * ((chanmap >> i) & 1);
diff --git a/libavutil/audioconvert.h b/libavutil/audioconvert.h
index e37a2e8..2069bd1 100644
--- a/libavutil/audioconvert.h
+++ b/libavutil/audioconvert.h
@@ -50,6 +50,10 @@
#define AV_CH_TOP_BACK_RIGHT 0x00020000
#define AV_CH_STEREO_LEFT 0x20000000 ///< Stereo downmix.
#define AV_CH_STEREO_RIGHT 0x40000000 ///< See AV_CH_STEREO_LEFT.
+#define AV_CH_LEFT_CENTER 0x80000000
+#define AV_CH_RIGHT_CENTER 0x100000000
+#define AV_CH_LEFT_SURROUND_DIRECT 0x200000000
+#define AV_CH_RIGHT_SURROUND_DIRECT 0x400000000
/** Channel mask value used for AVCodecContext.request_channel_layout
to indicate that the user requests the channel order of the decoder output
--------------1.7.1--
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