diff mbox

[FFmpeg-devel] lavf: add avformat_transfer_stream_timing_info() and use it in ffmpeg

Message ID 20160909150114.4019-1-u@pkh.me
State Superseded, archived
Headers show

Commit Message

Clément Bœsch Sept. 9, 2016, 3:01 p.m. UTC 
From: Clément Bœsch <clement@stupeflix.com>

In lavf we have access to st->internal->avctx so it's a better place
than in ffmpeg*.c and will allow moving to codecpar.

TODO: avformat.h doxy
TODO: version.h minor bump
TODO: doc/APIchanges update
---
 ffmpeg.c               | 51 +++-----------------------------------------
 libavformat/avformat.h | 12 +++++++++++
 libavformat/utils.c    | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 73 insertions(+), 48 deletions(-)
diff mbox

Patch

diff --git a/ffmpeg.c b/ffmpeg.c
index d858407..5c487c3 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -2909,57 +2909,12 @@  static int transcode_init(void)
             enc_ctx->bits_per_coded_sample  = dec_ctx->bits_per_coded_sample;
             enc_ctx->bits_per_raw_sample    = dec_ctx->bits_per_raw_sample;
 
-            enc_ctx->time_base = ist->st->time_base;
-            /*
-             * Avi is a special case here because it supports variable fps but
-             * having the fps and timebase differe significantly adds quite some
-             * overhead
-             */
-            if(!strcmp(oc->oformat->name, "avi")) {
-                if ( copy_tb<0 && ist->st->r_frame_rate.num
-                               && av_q2d(ist->st->r_frame_rate) >= av_q2d(ist->st->avg_frame_rate)
-                               && 0.5/av_q2d(ist->st->r_frame_rate) > av_q2d(ist->st->time_base)
-                               && 0.5/av_q2d(ist->st->r_frame_rate) > av_q2d(dec_ctx->time_base)
-                               && av_q2d(ist->st->time_base) < 1.0/500 && av_q2d(dec_ctx->time_base) < 1.0/500
-                     || copy_tb==2){
-                    enc_ctx->time_base.num = ist->st->r_frame_rate.den;
-                    enc_ctx->time_base.den = 2*ist->st->r_frame_rate.num;
-                    enc_ctx->ticks_per_frame = 2;
-                } else if (   copy_tb<0 && av_q2d(dec_ctx->time_base)*dec_ctx->ticks_per_frame > 2*av_q2d(ist->st->time_base)
-                                 && av_q2d(ist->st->time_base) < 1.0/500
-                    || copy_tb==0){
-                    enc_ctx->time_base = dec_ctx->time_base;
-                    enc_ctx->time_base.num *= dec_ctx->ticks_per_frame;
-                    enc_ctx->time_base.den *= 2;
-                    enc_ctx->ticks_per_frame = 2;
-                }
-            } else if(!(oc->oformat->flags & AVFMT_VARIABLE_FPS)
-                      && strcmp(oc->oformat->name, "mov") && strcmp(oc->oformat->name, "mp4") && strcmp(oc->oformat->name, "3gp")
-                      && strcmp(oc->oformat->name, "3g2") && strcmp(oc->oformat->name, "psp") && strcmp(oc->oformat->name, "ipod")
-                      && strcmp(oc->oformat->name, "f4v")
-            ) {
-                if(   copy_tb<0 && dec_ctx->time_base.den
-                                && av_q2d(dec_ctx->time_base)*dec_ctx->ticks_per_frame > av_q2d(ist->st->time_base)
-                                && av_q2d(ist->st->time_base) < 1.0/500
-                   || copy_tb==0){
-                    enc_ctx->time_base = dec_ctx->time_base;
-                    enc_ctx->time_base.num *= dec_ctx->ticks_per_frame;
-                }
-            }
-            if (   enc_ctx->codec_tag == AV_RL32("tmcd")
-                && dec_ctx->time_base.num < dec_ctx->time_base.den
-                && dec_ctx->time_base.num > 0
-                && 121LL*dec_ctx->time_base.num > dec_ctx->time_base.den) {
-                enc_ctx->time_base = dec_ctx->time_base;
-            }
+            ret = avformat_transfer_stream_timing_info(oc->oformat, ost->st, ist->st, copy_tb);
+            if (ret < 0)
+                return ret;
 
             if (!ost->frame_rate.num)
                 ost->frame_rate = ist->framerate;
-            if(ost->frame_rate.num)
-                enc_ctx->time_base = av_inv_q(ost->frame_rate);
-
-            av_reduce(&enc_ctx->time_base.num, &enc_ctx->time_base.den,
-                        enc_ctx->time_base.num, enc_ctx->time_base.den, INT_MAX);
 
             if (ist->st->nb_side_data) {
                 ost->st->side_data = av_realloc_array(NULL, ist->st->nb_side_data,
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 3ee7051..766e9b3 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -2893,6 +2893,18 @@  int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt,
                                AVBitStreamFilterContext *bsfc);
 #endif
 
+enum AVTimebaseCopyFrom {
+    AVFMT_TBCF_AUTO = -1,
+    AVFMT_TBCF_DECODER,
+    AVFMT_TBCF_DEMUXER,
+    AVFMT_TBCF_R_FRAMERATE,
+};
+
+// TODO: doc
+int avformat_transfer_stream_timing_info(const AVOutputFormat *ofmt,
+                                         AVStream *ost, const AVStream *ist,
+                                         enum AVTimebaseCopyFrom copy_tb);
+
 /**
  * @}
  */
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 76cbff4..e0c307f 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -5281,3 +5281,61 @@  int ff_bprint_to_codecpar_extradata(AVCodecParameters *par, struct AVBPrint *buf
     par->extradata_size = buf->len;
     return 0;
 }
+
+int avformat_transfer_stream_timing_info(const AVOutputFormat *ofmt,
+                                         AVStream *ost, const AVStream *ist,
+                                         enum AVTimebaseCopyFrom copy_tb)
+{
+    //TODO: use [io]st->internal->avctx
+    const AVCodecContext *dec_ctx = ist->codec;
+    AVCodecContext       *enc_ctx = ost->codec;
+
+    enc_ctx->time_base = ist->time_base;
+    /*
+     * Avi is a special case here because it supports variable fps but
+     * having the fps and timebase differe significantly adds quite some
+     * overhead
+     */
+    if (!strcmp(ofmt->name, "avi")) {
+        if (copy_tb == AVFMT_TBCF_AUTO && ist->r_frame_rate.num
+            && av_q2d(ist->r_frame_rate) >= av_q2d(ist->avg_frame_rate)
+            && 0.5/av_q2d(ist->r_frame_rate) > av_q2d(ist->time_base)
+            && 0.5/av_q2d(ist->r_frame_rate) > av_q2d(dec_ctx->time_base)
+            && av_q2d(ist->time_base) < 1.0/500 && av_q2d(dec_ctx->time_base) < 1.0/500
+            || copy_tb == AVFMT_TBCF_R_FRAMERATE) {
+            enc_ctx->time_base.num = ist->r_frame_rate.den;
+            enc_ctx->time_base.den = 2*ist->r_frame_rate.num;
+            enc_ctx->ticks_per_frame = 2;
+        } else if (copy_tb == AVFMT_TBCF_AUTO && av_q2d(dec_ctx->time_base)*dec_ctx->ticks_per_frame > 2*av_q2d(ist->time_base)
+                   && av_q2d(ist->time_base) < 1.0/500
+                   || copy_tb == AVFMT_TBCF_DECODER) {
+            enc_ctx->time_base = dec_ctx->time_base;
+            enc_ctx->time_base.num *= dec_ctx->ticks_per_frame;
+            enc_ctx->time_base.den *= 2;
+            enc_ctx->ticks_per_frame = 2;
+        }
+    } else if (!(ofmt->flags & AVFMT_VARIABLE_FPS)
+               && strcmp(ofmt->name, "mov") && strcmp(ofmt->name, "mp4") && strcmp(ofmt->name, "3gp")
+               && strcmp(ofmt->name, "3g2") && strcmp(ofmt->name, "psp") && strcmp(ofmt->name, "ipod")
+               && strcmp(ofmt->name, "f4v")) {
+        if (copy_tb == AVFMT_TBCF_AUTO && dec_ctx->time_base.den
+            && av_q2d(dec_ctx->time_base)*dec_ctx->ticks_per_frame > av_q2d(ist->time_base)
+            && av_q2d(ist->time_base) < 1.0/500
+            || copy_tb == AVFMT_TBCF_DECODER) {
+            enc_ctx->time_base = dec_ctx->time_base;
+            enc_ctx->time_base.num *= dec_ctx->ticks_per_frame;
+        }
+    }
+
+    if (enc_ctx->codec_tag == AV_RL32("tmcd")
+        && dec_ctx->time_base.num < dec_ctx->time_base.den
+        && dec_ctx->time_base.num > 0
+        && 121LL*dec_ctx->time_base.num > dec_ctx->time_base.den) {
+        enc_ctx->time_base = dec_ctx->time_base;
+    }
+
+    av_reduce(&enc_ctx->time_base.num, &enc_ctx->time_base.den,
+              enc_ctx->time_base.num, enc_ctx->time_base.den, INT_MAX);
+
+    return 0;
+}