[FFmpeg-devel] [PATCH] Default to using libraries when enabled

[Baptiste Coudurier]

On 5/23/10 3:33 PM, David Conrad wrote:
> On May 23, 2010, at 6:04 PM, Baptiste Coudurier wrote:
>
>> On 5/23/10 2:59 PM, Janne Grunau wrote:
>>> On Sun, May 23, 2010 at 06:41:35PM +0200, Michael Niedermayer wrote:
>>>> On Sat, May 22, 2010 at 12:48:02PM +0200, Janne Grunau wrote:
>>>>> See attached patches for selections by codec id. Beside the aac and vorbis
>>>>> encoder are there other codecs which should be considered experimental?
>>>>> It's more tricky for selections by codec name since the names are unique.
>>>>> The best solution is probably to fail in ffmpeg if the encoder is experimental
>>>>> and -strict (or something else) is not set.
>>>>
>>>>>   avcodec.h |    4 ++++
>>>>>   utils.c   |   24 ++++++++++++++++--------
>>>>>   2 files changed, 20 insertions(+), 8 deletions(-)
>>>>> 62657abb5bcdd4c0791216099c04dc0e3b6cde36  avoid_experimental_codecs.diff
>>>>> commit 75273f4917cf21fcab6da91c048fae5955012b68
>>>>> Author: Janne Grunau<janne at grunau.be>
>>>>> Date:   Sat May 22 02:19:30 2010 +0200
>>>>>
>>>>>      add CODEC_CAP_EXPERIMENTAL and prefer codecs without this capability
>>>>>
>>>>>      avcodec_find_{de|en}coder returns only imidiately if CODEC_CAP_EXPERIMENTAL
>>>>>      is not set. The first experimental codec is saved and returned if no other
>>>>>      codec was found.
>>>>>
>>>>> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
>>>>> index 8781c0a..a0d6498 100644
>>>>> --- a/libavcodec/avcodec.h
>>>>> +++ b/libavcodec/avcodec.h
>>>>> @@ -645,6 +645,10 @@ typedef struct RcOverride{
>>>>>    * as a last resort.
>>>>>    */
>>>>>   #define CODEC_CAP_SUBFRAMES        0x0100
>>>>> +/**
>>>>> + * Codec is experimental
>>>>
>>>> // and is thus avoided in favor of non experimental encoders
>>>
>>> updated patch attached
>>>
>>>> the rest of the patch is ok with me
>>>
>>> Janne
>>>
>>>
>>> avoid_experimental_codecs2.diff
>>>
>>>
>>> commit 35cda412179490370d56223c5bbd5dd29b35a9f6
>>> Author: Janne Grunau<janne at grunau.be>
>>> Date:   Sat May 22 02:19:30 2010 +0200
>>>
>>>      add CODEC_CAP_EXPERIMENTAL and prefer codecs without this capability
>>>
>>>      avcodec_find_{de|en}coder returns only imidiately if CODEC_CAP_EXPERIMENTAL
>>>      is not set. The first experimental codec is saved and returned if no other
>>>      codec was found.
>>>
>>> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
>>> index cd642ac..5e54953 100644
>>> --- a/libavcodec/avcodec.h
>>> +++ b/libavcodec/avcodec.h
>>> @@ -645,6 +645,11 @@ typedef struct RcOverride{
>>>    * as a last resort.
>>>    */
>>>   #define CODEC_CAP_SUBFRAMES        0x0100
>>> +/**
>>> + * Codec is experimental and is thus avoided in favor of non experimental
>>> + * encoders
>>> + */
>>> +#define CODEC_CAP_EXPERIMENTAL     0x0200
>>>
>>>   //The following defines may change, don't expect compatibility if you use them.
>>>   #define MB_TYPE_INTRA4x4   0x0001
>>> diff --git a/libavcodec/utils.c b/libavcodec/utils.c
>>> index 56d4dbd..978e4d3 100644
>>> --- a/libavcodec/utils.c
>>> +++ b/libavcodec/utils.c
>>> @@ -725,14 +725,18 @@ av_cold int avcodec_close(AVCodecContext *avctx)
>>>
>>>   AVCodec *avcodec_find_encoder(enum CodecID id)
>>>   {
>>> -    AVCodec *p;
>>> +    AVCodec *p, *experimental=NULL;
>>>       p = first_avcodec;
>>>       while (p) {
>>> -        if (p->encode != NULL&&   p->id == id)
>>> -            return p;
>>> +        if (p->encode != NULL&&   p->id == id) {
>>> +            if (p->capabilities&   CODEC_CAP_EXPERIMENTAL&&   !experimental)
>>> +                experimental = p;
>>> +            else
>>> +                return p;
>>> +        }
>>>           p = p->next;
>>>       }
>>> -    return NULL;
>>> +    return experimental;
>>>   }
>>>
>>>   AVCodec *avcodec_find_encoder_by_name(const char *name)
>>> @@ -751,14 +755,18 @@ AVCodec *avcodec_find_encoder_by_name(const char *name)
>>>
>>>   AVCodec *avcodec_find_decoder(enum CodecID id)
>>>   {
>>> -    AVCodec *p;
>>> +    AVCodec *p, *experimental=NULL;
>>>       p = first_avcodec;
>>>       while (p) {
>>> -        if (p->decode != NULL&&   p->id == id)
>>> -            return p;
>>> +        if (p->decode != NULL&&   p->id == id) {
>>> +            if (p->capabilities&   CODEC_CAP_EXPERIMENTAL&&   !experimental)
>>> +                experimental = p;
>>> +            else
>>> +                return p;
>>> +        }
>>>           p = p->next;
>>>       }
>>> -    return NULL;
>>> +    return experimental;
>>>   }
>>>
>>>   AVCodec *avcodec_find_decoder_by_name(const char *name)
>>>
>>
>> Humm won't this have side effects for decoder developpers ?
>>
>> Manually selecting encoders is easy, but not decoders.
>>
>> For encoders I think I'm ok.
>
> For ffmpeg, -vcodec before the -i works for me. It probably ought to be added to ffplay.

I was more thinking about av_find_stream_info for decoding the first frames.

-- 
Baptiste COUDURIER
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