Set AVCodecContext.request_channel_layout when decoding.

Allows extracting a 5.1 or 2-channel downmix from a dedicated substream (TrueHD).

Also works around a bug when decoding TrueHD Mono.



git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5242 b64f7644-9d1e-0410-96f1-a4d463321fa5

1 files changed, 46 insertions, 0 deletions

diff --git a/contrib/ffmpeg/A05-truehd-downmix.patch b/contrib/ffmpeg/A05-truehd-downmix.patch
new file mode 100644
index 000000000..35344613f
--- /dev/null
+++ b/contrib/ffmpeg/A05-truehd-downmix.patch
@@ -0,0 +1,46 @@
+diff --git a/libavcodec/mlpdec.c b/libavcodec/mlpdec.c
+index 3852f6e..86aecf7 100644
+--- a/libavcodec/mlpdec.c
++++ b/libavcodec/mlpdec.c
+@@ -394,14 +394,24 @@ static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,
+         return AVERROR_INVALIDDATA;
+     }
+ 
+-    if (m->avctx->request_channels > 0
+-        && s->max_channel + 1 >= m->avctx->request_channels
+-        && substr < m->max_decoded_substream) {
++#if FF_API_REQUEST_CHANNELS
++    if (m->avctx->request_channels > 0 &&
++        m->avctx->request_channels <= s->max_channel + 1 &&
++        m->max_decoded_substream > substr) {
+         av_log(m->avctx, AV_LOG_DEBUG,
+-               "Extracting %d channel downmix from substream %d. "
++               "Extracting %d-channel downmix from substream %d. "
+                "Further substreams will be skipped.\n",
+                s->max_channel + 1, substr);
+         m->max_decoded_substream = substr;
++    } else
++#endif
++    if (m->avctx->request_channel_layout == s->ch_layout &&
++        m->max_decoded_substream > substr) {
++        av_log(m->avctx, AV_LOG_DEBUG,
++               "Extracting %d-channel downmix (0x%"PRIx64") from substream %d. "
++               "Further substreams will be skipped.\n",
++               s->max_channel + 1, s->ch_layout, substr);
++        m->max_decoded_substream = substr;
+     }
+ 
+     s->noise_shift   = get_bits(gbp,  4);
+@@ -463,8 +473,10 @@ static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,
+         cp->huff_lsbs        = 24;
+     }
+ 
+-    if (substr == m->max_decoded_substream)
+-        m->avctx->channels = s->max_matrix_channel + 1;
++    if (substr == m->max_decoded_substream) {
++        m->avctx->channels       = s->max_matrix_channel + 1;
++        m->avctx->channel_layout = s->ch_layout;
++    }
+ 
+     return 0;
+ }