Re: [FFmpeg-devel] [PATCH] lavfi/atempo: raise max tempo limit (v2)

2018-06-14 Thread Pavel Koshevoy 

On 06/13/2018 07:39 AM, Pavel Koshevoy wrote:

On Thu, Jun 7, 2018 at 8:16 PM Pavel Koshevoy  wrote:

---
  doc/filters.texi| 17 ++---
  libavfilter/af_atempo.c |  6 +++---
  2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/doc/filters.texi b/doc/filters.texi
index 256ab42b00..6b98b04774 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -1986,7 +1986,12 @@ Adjust audio tempo.

  The filter accepts exactly one parameter, the audio tempo. If not
  specified then the filter will assume nominal 1.0 tempo. Tempo must
-be in the [0.5, 2.0] range.
+be in the [0.5, 100.0] range.
+
+Note that tempo greater than 2 will skip some samples rather than
+blend them in.  If for any reason this is a concern it is always
+possible to daisy-chain several instances of atempo to achieve the
+desired product tempo.

  @subsection Examples

@@ -1998,9 +2003,15 @@ atempo=0.8
  @end example

  @item
-To speed up audio to 125% tempo:
+To speed up audio to 300% tempo:
+@example
+atempo=3
+@end example
+
+@item
+To speed up audio to 300% tempo by daisy-chaining two atempo instances:
  @example
-atempo=1.25
+atempo=sqrt(3),atempo=sqrt(3)
  @end example
  @end itemize

diff --git a/libavfilter/af_atempo.c b/libavfilter/af_atempo.c
index 8b214bccd7..52f15f2769 100644
--- a/libavfilter/af_atempo.c
+++ b/libavfilter/af_atempo.c
@@ -153,7 +153,7 @@ typedef struct ATempoContext {

  static const AVOption atempo_options[] = {
  { "tempo", "set tempo scale factor",
-  OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 2.0,
+  OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 100.0,
AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM },
  { NULL }
  };
@@ -439,8 +439,8 @@ static int yae_load_data(ATempoContext *atempo,
  return 0;
  }

-// samples are not expected to be skipped:
-av_assert0(read_size <= atempo->ring);
+// samples are not expected to be skipped, unless tempo is greater than 2:
+av_assert0(read_size <= atempo->ring || atempo->tempo > 2.0);

  while (atempo->position[0] < stop_here && src < src_end) {
  int src_samples = (src_end - src) / atempo->stride;
--
2.16.4



Any objections if I apply this?

 Pavel.




Applied, pushed

    Pavel.

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Re: [FFmpeg-devel] [PATCH] lavfi/atempo: raise max tempo limit (v2)

2018-06-13 Thread Pavel Koshevoy 
On Thu, Jun 7, 2018 at 8:16 PM Pavel Koshevoy  wrote:
>
> ---
>  doc/filters.texi| 17 ++---
>  libavfilter/af_atempo.c |  6 +++---
>  2 files changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 256ab42b00..6b98b04774 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -1986,7 +1986,12 @@ Adjust audio tempo.
>
>  The filter accepts exactly one parameter, the audio tempo. If not
>  specified then the filter will assume nominal 1.0 tempo. Tempo must
> -be in the [0.5, 2.0] range.
> +be in the [0.5, 100.0] range.
> +
> +Note that tempo greater than 2 will skip some samples rather than
> +blend them in.  If for any reason this is a concern it is always
> +possible to daisy-chain several instances of atempo to achieve the
> +desired product tempo.
>
>  @subsection Examples
>
> @@ -1998,9 +2003,15 @@ atempo=0.8
>  @end example
>
>  @item
> -To speed up audio to 125% tempo:
> +To speed up audio to 300% tempo:
> +@example
> +atempo=3
> +@end example
> +
> +@item
> +To speed up audio to 300% tempo by daisy-chaining two atempo instances:
>  @example
> -atempo=1.25
> +atempo=sqrt(3),atempo=sqrt(3)
>  @end example
>  @end itemize
>
> diff --git a/libavfilter/af_atempo.c b/libavfilter/af_atempo.c
> index 8b214bccd7..52f15f2769 100644
> --- a/libavfilter/af_atempo.c
> +++ b/libavfilter/af_atempo.c
> @@ -153,7 +153,7 @@ typedef struct ATempoContext {
>
>  static const AVOption atempo_options[] = {
>  { "tempo", "set tempo scale factor",
> -  OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 2.0,
> +  OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 100.0,
>AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM },
>  { NULL }
>  };
> @@ -439,8 +439,8 @@ static int yae_load_data(ATempoContext *atempo,
>  return 0;
>  }
>
> -// samples are not expected to be skipped:
> -av_assert0(read_size <= atempo->ring);
> +// samples are not expected to be skipped, unless tempo is greater than 
> 2:
> +av_assert0(read_size <= atempo->ring || atempo->tempo > 2.0);
>
>  while (atempo->position[0] < stop_here && src < src_end) {
>  int src_samples = (src_end - src) / atempo->stride;
> --
> 2.16.4
>


Any objections if I apply this?

Pavel.
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[FFmpeg-devel] [PATCH] lavfi/atempo: raise max tempo limit (v2)

2018-06-07 Thread Pavel Koshevoy 
---
 doc/filters.texi| 17 ++---
 libavfilter/af_atempo.c |  6 +++---
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/doc/filters.texi b/doc/filters.texi
index 256ab42b00..6b98b04774 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -1986,7 +1986,12 @@ Adjust audio tempo.
 
 The filter accepts exactly one parameter, the audio tempo. If not
 specified then the filter will assume nominal 1.0 tempo. Tempo must
-be in the [0.5, 2.0] range.
+be in the [0.5, 100.0] range.
+
+Note that tempo greater than 2 will skip some samples rather than
+blend them in.  If for any reason this is a concern it is always
+possible to daisy-chain several instances of atempo to achieve the
+desired product tempo.
 
 @subsection Examples
 
@@ -1998,9 +2003,15 @@ atempo=0.8
 @end example
 
 @item
-To speed up audio to 125% tempo:
+To speed up audio to 300% tempo:
+@example
+atempo=3
+@end example
+
+@item
+To speed up audio to 300% tempo by daisy-chaining two atempo instances:
 @example
-atempo=1.25
+atempo=sqrt(3),atempo=sqrt(3)
 @end example
 @end itemize
 
diff --git a/libavfilter/af_atempo.c b/libavfilter/af_atempo.c
index 8b214bccd7..52f15f2769 100644
--- a/libavfilter/af_atempo.c
+++ b/libavfilter/af_atempo.c
@@ -153,7 +153,7 @@ typedef struct ATempoContext {
 
 static const AVOption atempo_options[] = {
 { "tempo", "set tempo scale factor",
-  OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 2.0,
+  OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 100.0,
   AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM },
 { NULL }
 };
@@ -439,8 +439,8 @@ static int yae_load_data(ATempoContext *atempo,
 return 0;
 }
 
-// samples are not expected to be skipped:
-av_assert0(read_size <= atempo->ring);
+// samples are not expected to be skipped, unless tempo is greater than 2:
+av_assert0(read_size <= atempo->ring || atempo->tempo > 2.0);
 
 while (atempo->position[0] < stop_here && src < src_end) {
 int src_samples = (src_end - src) / atempo->stride;
-- 
2.16.4

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Re: [FFmpeg-devel] [PATCH] lavfi/atempo: raise max tempo limit

2018-06-07 Thread Moritz Barsnick 
On Tue, Jun 05, 2018 at 20:59:16 -0600, Pavel Koshevoy wrote:
> ---
>  libavfilter/af_atempo.c | 5 +
>  1 file changed, 1 insertion(+), 4 deletions(-)

Please have a look at doc/filters.texi and adapt the atempo section in
the same commit.

Moritz
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Re: [FFmpeg-devel] [PATCH] lavfi/atempo: raise max tempo limit

2018-06-05 Thread Pavel Koshevoy 
On Tue, Jun 5, 2018 at 8:59 PM, Pavel Koshevoy  wrote:
> ---
>  libavfilter/af_atempo.c | 5 +
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/libavfilter/af_atempo.c b/libavfilter/af_atempo.c
> index 8b214bccd7..daf4693321 100644
> --- a/libavfilter/af_atempo.c
> +++ b/libavfilter/af_atempo.c
> @@ -153,7 +153,7 @@ typedef struct ATempoContext {
>
>  static const AVOption atempo_options[] = {
>  { "tempo", "set tempo scale factor",
> -  OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 2.0,
> +  OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 100.0,
>AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM },
>  { NULL }
>  };
> @@ -439,9 +439,6 @@ static int yae_load_data(ATempoContext *atempo,
>  return 0;
>  }
>
> -// samples are not expected to be skipped:
> -av_assert0(read_size <= atempo->ring);
> -
>  while (atempo->position[0] < stop_here && src < src_end) {
>  int src_samples = (src_end - src) / atempo->stride;
>
> --
> 2.16.3
>


I've tested with atempo=3, 4, 5, 6, 7, 30, 100...  It sounds reasonable.
I've compared atempo=3 vs 'atempo=sqrt(3.0),atempo=sqrt(3.0)' and did
not hear any difference.

I've removed the assertion because at tempo >= 7 the assertion fails,
but I'm not concerned about it -- some samples will simply be dropped
rather than being blended in.  At that high tempo I don't think
including all samples in output is a foremost consideration.  If
someone is concerned about samples being dropped from output stream
they can still fall back to the technique of daisy-chaining several
atempo instances at lower tempo setting.

If the patch looks good to someone with commit rights -- please apply.

Thank you,
  Pavel.
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[FFmpeg-devel] [PATCH] lavfi/atempo: raise max tempo limit

2018-06-05 Thread Pavel Koshevoy 
---
 libavfilter/af_atempo.c | 5 +
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/libavfilter/af_atempo.c b/libavfilter/af_atempo.c
index 8b214bccd7..daf4693321 100644
--- a/libavfilter/af_atempo.c
+++ b/libavfilter/af_atempo.c
@@ -153,7 +153,7 @@ typedef struct ATempoContext {
 
 static const AVOption atempo_options[] = {
 { "tempo", "set tempo scale factor",
-  OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 2.0,
+  OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 100.0,
   AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM },
 { NULL }
 };
@@ -439,9 +439,6 @@ static int yae_load_data(ATempoContext *atempo,
 return 0;
 }
 
-// samples are not expected to be skipped:
-av_assert0(read_size <= atempo->ring);
-
 while (atempo->position[0] < stop_here && src < src_end) {
 int src_samples = (src_end - src) / atempo->stride;
 
-- 
2.16.3

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