[FFmpeg-devel,01/13] avformat/mux: Move packet references

Submitted by Andreas Rheinhardt on Aug. 13, 2019, 2:47 a.m.

Details

Message ID 20190813024726.6596-1-andreas.rheinhardt@gmail.com
State New
Headers show

Commit Message

Andreas Rheinhardt Aug. 13, 2019, 2:47 a.m.
In the common case that the input packet was already refcounted,
ff_interleave_add_packet would allocate a new AVPacketList, use
av_packet_ref to create a new reference to the buffer for the
AVPacketList's packet, interleave the packet and finally unreference
the original input packet.
This commit changes this: It uses av_packet_move_ref to transfer
the packet to its destination. In case the input packet is refcounted,
this saves an allocation and a free (of an AVBufferRef); if not, the
packet is made refcounted before moving it. When the input packet has
side data, one saves even more than one allocation+free.

Furthermore, when the packet is in reality an uncoded frame, a hacky
ad-hoc variant of av_packet_move_ref has been employed. Not any more.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
---
 libavformat/mux.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

Comments

Andreas Rheinhardt Sept. 15, 2019, 11:22 a.m.
Andreas Rheinhardt:
> In the common case that the input packet was already refcounted,
> ff_interleave_add_packet would allocate a new AVPacketList, use
> av_packet_ref to create a new reference to the buffer for the
> AVPacketList's packet, interleave the packet and finally unreference
> the original input packet.
> This commit changes this: It uses av_packet_move_ref to transfer
> the packet to its destination. In case the input packet is refcounted,
> this saves an allocation and a free (of an AVBufferRef); if not, the
> packet is made refcounted before moving it. When the input packet has
> side data, one saves even more than one allocation+free.
> 
> Furthermore, when the packet is in reality an uncoded frame, a hacky
> ad-hoc variant of av_packet_move_ref has been employed. Not any more.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
> ---
>  libavformat/mux.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/libavformat/mux.c b/libavformat/mux.c
> index 8ab5ea8c2b..ac370fb24d 100644
> --- a/libavformat/mux.c
> +++ b/libavformat/mux.c
> @@ -930,17 +930,16 @@ int ff_interleave_add_packet(AVFormatContext *s, AVPacket *pkt,
>      if ((pkt->flags & AV_PKT_FLAG_UNCODED_FRAME)) {
>          av_assert0(pkt->size == UNCODED_FRAME_PACKET_SIZE);
>          av_assert0(((AVFrame *)pkt->data)->buf);
> -        this_pktl->pkt = *pkt;
> -        pkt->buf = NULL;
> -        pkt->side_data = NULL;
> -        pkt->side_data_elems = 0;
>      } else {
> -        if ((ret = av_packet_ref(&this_pktl->pkt, pkt)) < 0) {
> +        if ((ret = av_packet_make_refcounted(pkt)) < 0) {
>              av_free(this_pktl);
>              return ret;
>          }
>      }
>  
> +    av_packet_move_ref(&this_pktl->pkt, pkt);
> +    pkt = &this_pktl->pkt;
> +
>      if (s->streams[pkt->stream_index]->last_in_packet_buffer) {
>          next_point = &(st->last_in_packet_buffer->next);
>      } else {
> @@ -989,8 +988,6 @@ next_non_null:
>      s->streams[pkt->stream_index]->last_in_packet_buffer =
>          *next_point                                      = this_pktl;
>  
> -    av_packet_unref(pkt);
> -
>      return 0;
>  }
>  
> 
Ping for this patch and the remaining unmerged patches in this
patchset (patches 1, 2, 4, 5, 7-13).

- Andreas
Andreas Rheinhardt Sept. 25, 2019, 10:57 a.m.
Andreas Rheinhardt:
> Andreas Rheinhardt:
>> In the common case that the input packet was already refcounted,
>> ff_interleave_add_packet would allocate a new AVPacketList, use
>> av_packet_ref to create a new reference to the buffer for the
>> AVPacketList's packet, interleave the packet and finally unreference
>> the original input packet.
>> This commit changes this: It uses av_packet_move_ref to transfer
>> the packet to its destination. In case the input packet is refcounted,
>> this saves an allocation and a free (of an AVBufferRef); if not, the
>> packet is made refcounted before moving it. When the input packet has
>> side data, one saves even more than one allocation+free.
>>
>> Furthermore, when the packet is in reality an uncoded frame, a hacky
>> ad-hoc variant of av_packet_move_ref has been employed. Not any more.
>>
>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
>> ---
>>  libavformat/mux.c | 11 ++++-------
>>  1 file changed, 4 insertions(+), 7 deletions(-)
>>
>> diff --git a/libavformat/mux.c b/libavformat/mux.c
>> index 8ab5ea8c2b..ac370fb24d 100644
>> --- a/libavformat/mux.c
>> +++ b/libavformat/mux.c
>> @@ -930,17 +930,16 @@ int ff_interleave_add_packet(AVFormatContext *s, AVPacket *pkt,
>>      if ((pkt->flags & AV_PKT_FLAG_UNCODED_FRAME)) {
>>          av_assert0(pkt->size == UNCODED_FRAME_PACKET_SIZE);
>>          av_assert0(((AVFrame *)pkt->data)->buf);
>> -        this_pktl->pkt = *pkt;
>> -        pkt->buf = NULL;
>> -        pkt->side_data = NULL;
>> -        pkt->side_data_elems = 0;
>>      } else {
>> -        if ((ret = av_packet_ref(&this_pktl->pkt, pkt)) < 0) {
>> +        if ((ret = av_packet_make_refcounted(pkt)) < 0) {
>>              av_free(this_pktl);
>>              return ret;
>>          }
>>      }
>>  
>> +    av_packet_move_ref(&this_pktl->pkt, pkt);
>> +    pkt = &this_pktl->pkt;
>> +
>>      if (s->streams[pkt->stream_index]->last_in_packet_buffer) {
>>          next_point = &(st->last_in_packet_buffer->next);
>>      } else {
>> @@ -989,8 +988,6 @@ next_non_null:
>>      s->streams[pkt->stream_index]->last_in_packet_buffer =
>>          *next_point                                      = this_pktl;
>>  
>> -    av_packet_unref(pkt);
>> -
>>      return 0;
>>  }
>>  
>>
> Ping for this patch and the remaining unmerged patches in this
> patchset (patches 1, 2, 4, 5, 7-13).
> 
> - Andreas
> 
Another ping.

- Andreas
Andreas Rheinhardt Oct. 8, 2019, 10:42 a.m.
Andreas Rheinhardt:
> Andreas Rheinhardt:
>> In the common case that the input packet was already refcounted,
>> ff_interleave_add_packet would allocate a new AVPacketList, use
>> av_packet_ref to create a new reference to the buffer for the
>> AVPacketList's packet, interleave the packet and finally unreference
>> the original input packet.
>> This commit changes this: It uses av_packet_move_ref to transfer
>> the packet to its destination. In case the input packet is refcounted,
>> this saves an allocation and a free (of an AVBufferRef); if not, the
>> packet is made refcounted before moving it. When the input packet has
>> side data, one saves even more than one allocation+free.
>>
>> Furthermore, when the packet is in reality an uncoded frame, a hacky
>> ad-hoc variant of av_packet_move_ref has been employed. Not any more.
>>
>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
>> ---
>>  libavformat/mux.c | 11 ++++-------
>>  1 file changed, 4 insertions(+), 7 deletions(-)
>>
>> diff --git a/libavformat/mux.c b/libavformat/mux.c
>> index 8ab5ea8c2b..ac370fb24d 100644
>> --- a/libavformat/mux.c
>> +++ b/libavformat/mux.c
>> @@ -930,17 +930,16 @@ int ff_interleave_add_packet(AVFormatContext *s, AVPacket *pkt,
>>      if ((pkt->flags & AV_PKT_FLAG_UNCODED_FRAME)) {
>>          av_assert0(pkt->size == UNCODED_FRAME_PACKET_SIZE);
>>          av_assert0(((AVFrame *)pkt->data)->buf);
>> -        this_pktl->pkt = *pkt;
>> -        pkt->buf = NULL;
>> -        pkt->side_data = NULL;
>> -        pkt->side_data_elems = 0;
>>      } else {
>> -        if ((ret = av_packet_ref(&this_pktl->pkt, pkt)) < 0) {
>> +        if ((ret = av_packet_make_refcounted(pkt)) < 0) {
>>              av_free(this_pktl);
>>              return ret;
>>          }
>>      }
>>  
>> +    av_packet_move_ref(&this_pktl->pkt, pkt);
>> +    pkt = &this_pktl->pkt;
>> +
>>      if (s->streams[pkt->stream_index]->last_in_packet_buffer) {
>>          next_point = &(st->last_in_packet_buffer->next);
>>      } else {
>> @@ -989,8 +988,6 @@ next_non_null:
>>      s->streams[pkt->stream_index]->last_in_packet_buffer =
>>          *next_point                                      = this_pktl;
>>  
>> -    av_packet_unref(pkt);
>> -
>>      return 0;
>>  }
>>  
>>
> Ping for this patch and the remaining unmerged patches in this
> patchset (patches 1, 2, 4, 5, 7-13).
> 
> - Andreas
> 
Another ping.

- Andreas

Patch hide | download patch | download mbox

diff --git a/libavformat/mux.c b/libavformat/mux.c
index 8ab5ea8c2b..ac370fb24d 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -930,17 +930,16 @@  int ff_interleave_add_packet(AVFormatContext *s, AVPacket *pkt,
     if ((pkt->flags & AV_PKT_FLAG_UNCODED_FRAME)) {
         av_assert0(pkt->size == UNCODED_FRAME_PACKET_SIZE);
         av_assert0(((AVFrame *)pkt->data)->buf);
-        this_pktl->pkt = *pkt;
-        pkt->buf = NULL;
-        pkt->side_data = NULL;
-        pkt->side_data_elems = 0;
     } else {
-        if ((ret = av_packet_ref(&this_pktl->pkt, pkt)) < 0) {
+        if ((ret = av_packet_make_refcounted(pkt)) < 0) {
             av_free(this_pktl);
             return ret;
         }
     }
 
+    av_packet_move_ref(&this_pktl->pkt, pkt);
+    pkt = &this_pktl->pkt;
+
     if (s->streams[pkt->stream_index]->last_in_packet_buffer) {
         next_point = &(st->last_in_packet_buffer->next);
     } else {
@@ -989,8 +988,6 @@  next_non_null:
     s->streams[pkt->stream_index]->last_in_packet_buffer =
         *next_point                                      = this_pktl;
 
-    av_packet_unref(pkt);
-
     return 0;
 }