viddec: avoid renegotiation

Keep track of the context veriables and renegotiate when something changes. We
need to use separate values for this because not all values can be copied into a
GstVideoInfo.
Set the output interlacing based on the libav context.
Use the demuxer and decoder framerate to construct an output framerate.
Use demuxer and decoder par to construct an output framerate.

diff --git a/ext/ffmpeg/gstffmpegviddec.c b/ext/ffmpeg/gstffmpegviddec.c
index 0ad1402..bdb2e43 100644 (file)
--- a/ext/ffmpeg/gstffmpegviddec.c
+++ b/ext/ffmpeg/gstffmpegviddec.c
@@ -58,7 +58,17 @@ struct _GstFFMpegVidDec
   AVFrame *picture;
   gboolean opened;
 
-  enum PixelFormat pix_fmt;
+  /* current context */
+  enum PixelFormat ctx_pix_fmt;
+  gint ctx_width;
+  gint ctx_height;
+  gint ctx_par_n;
+  gint ctx_par_d;
+  gint ctx_ticks;
+  gint ctx_time_d;
+  gint ctx_time_n;
+  gint ctx_interlaced;
+
   gboolean waiting_for_key;
 
   /* for tracking DTS/PTS */
@@ -379,8 +389,6 @@ gst_ffmpegviddec_open (GstFFMpegVidDec * ffmpegdec)
       break;
   }
 
-  ffmpegdec->pix_fmt = PIX_FMT_NB;
-
   return TRUE;
 
   /* ERRORS */
@@ -660,50 +668,174 @@ gst_ffmpegviddec_release_buffer (AVCodecContext * context, AVFrame * picture)
 }
 
 static gboolean
-gst_ffmpegviddec_negotiate (GstFFMpegVidDec * ffmpegdec, gboolean force)
+update_video_context (GstFFMpegVidDec * ffmpegdec, gboolean force)
 {
-  GstVideoInfo *info;
   AVCodecContext *context = ffmpegdec->context;
-  GstVideoFormat fmt;
-  GstVideoCodecState *output_format;
-
-  info = &ffmpegdec->input_state->info;
-  if (!force && GST_VIDEO_INFO_WIDTH (info) == context->width
-      && GST_VIDEO_INFO_HEIGHT (info) == context->height
-      && GST_VIDEO_INFO_PAR_N (info) == context->sample_aspect_ratio.num
-      && GST_VIDEO_INFO_PAR_D (info) == context->sample_aspect_ratio.den
-      && ffmpegdec->pix_fmt == context->pix_fmt)
-    return TRUE;
+
+  if (!force && ffmpegdec->ctx_width == context->width
+      && ffmpegdec->ctx_height == context->height
+      && ffmpegdec->ctx_ticks == context->ticks_per_frame
+      && ffmpegdec->ctx_time_n == context->time_base.num
+      && ffmpegdec->ctx_time_d == context->time_base.den
+      && ffmpegdec->ctx_pix_fmt == context->pix_fmt
+      && ffmpegdec->ctx_par_n == context->sample_aspect_ratio.num
+      && ffmpegdec->ctx_par_d == context->sample_aspect_ratio.den)
+    return FALSE;
 
   GST_DEBUG_OBJECT (ffmpegdec,
-      "Renegotiating video from %dx%d@ (PAR %d:%d, %d/%d fps) to %dx%d@ (PAR %d:%d, %d/%d fps)",
-      GST_VIDEO_INFO_WIDTH (info), GST_VIDEO_INFO_HEIGHT (info),
-      GST_VIDEO_INFO_PAR_N (info), GST_VIDEO_INFO_PAR_D (info),
-      GST_VIDEO_INFO_FPS_N (info), GST_VIDEO_INFO_FPS_D (info),
+      "Renegotiating video from %dx%d@ %d:%d PAR %d/%d fps to %dx%d@ %d:%d PAR %d/%d fps pixfmt %d",
+      ffmpegdec->ctx_width, ffmpegdec->ctx_height,
+      ffmpegdec->ctx_par_n, ffmpegdec->ctx_par_d,
+      ffmpegdec->ctx_time_n, ffmpegdec->ctx_time_d,
       context->width, context->height,
       context->sample_aspect_ratio.num,
-      context->sample_aspect_ratio.den, -1, -1);
+      context->sample_aspect_ratio.den,
+      context->time_base.num, context->time_base.den, context->pix_fmt);
+
+  ffmpegdec->ctx_width = context->width;
+  ffmpegdec->ctx_height = context->height;
+  ffmpegdec->ctx_ticks = context->ticks_per_frame;
+  ffmpegdec->ctx_time_n = context->time_base.num;
+  ffmpegdec->ctx_time_d = context->time_base.den;
+  ffmpegdec->ctx_pix_fmt = context->pix_fmt;
+  ffmpegdec->ctx_par_n = context->sample_aspect_ratio.num;
+  ffmpegdec->ctx_par_d = context->sample_aspect_ratio.den;
+
+  return TRUE;
+}
+
+static void
+gst_ffmpegviddec_update_par (GstFFMpegVidDec * ffmpegdec,
+    GstVideoInfo * in_info, GstVideoInfo * out_info)
+{
+  gboolean demuxer_par_set = FALSE;
+  gboolean decoder_par_set = FALSE;
+  gint demuxer_num = 1, demuxer_denom = 1;
+  gint decoder_num = 1, decoder_denom = 1;
+
+  if (in_info->par_n && in_info->par_d) {
+    demuxer_num = in_info->par_n;
+    demuxer_denom = in_info->par_d;
+    demuxer_par_set = TRUE;
+    GST_DEBUG_OBJECT (ffmpegdec, "Demuxer PAR: %d:%d", demuxer_num,
+        demuxer_denom);
+  }
 
-  /* Remember current pix_fmt */
-  ffmpegdec->pix_fmt = context->pix_fmt;
-  fmt = gst_ffmpeg_pixfmt_to_videoformat (context->pix_fmt);
+  if (ffmpegdec->ctx_par_n && ffmpegdec->ctx_par_d) {
+    decoder_num = ffmpegdec->ctx_par_n;
+    decoder_denom = ffmpegdec->ctx_par_d;
+    decoder_par_set = TRUE;
+    GST_DEBUG_OBJECT (ffmpegdec, "Decoder PAR: %d:%d", decoder_num,
+        decoder_denom);
+  }
+
+  if (!demuxer_par_set && !decoder_par_set)
+    goto no_par;
+
+  if (demuxer_par_set && !decoder_par_set)
+    goto use_demuxer_par;
+
+  if (decoder_par_set && !demuxer_par_set)
+    goto use_decoder_par;
 
+  /* Both the demuxer and the decoder provide a PAR. If one of
+   * the two PARs is 1:1 and the other one is not, use the one
+   * that is not 1:1. */
+  if (demuxer_num == demuxer_denom && decoder_num != decoder_denom)
+    goto use_decoder_par;
+
+  if (decoder_num == decoder_denom && demuxer_num != demuxer_denom)
+    goto use_demuxer_par;
+
+  /* Both PARs are non-1:1, so use the PAR provided by the demuxer */
+  goto use_demuxer_par;
+
+use_decoder_par:
+  {
+    GST_DEBUG_OBJECT (ffmpegdec,
+        "Setting decoder provided pixel-aspect-ratio of %u:%u", decoder_num,
+        decoder_denom);
+    out_info->par_n = decoder_num;
+    out_info->par_d = decoder_denom;
+    return;
+  }
+use_demuxer_par:
+  {
+    GST_DEBUG_OBJECT (ffmpegdec,
+        "Setting demuxer provided pixel-aspect-ratio of %u:%u", demuxer_num,
+        demuxer_denom);
+    out_info->par_n = demuxer_num;
+    out_info->par_d = demuxer_denom;
+    return;
+  }
+no_par:
+  {
+    GST_DEBUG_OBJECT (ffmpegdec,
+        "Neither demuxer nor codec provide a pixel-aspect-ratio");
+    out_info->par_n = 1;
+    out_info->par_d = 1;
+    return;
+  }
+}
+
+static gboolean
+gst_ffmpegviddec_negotiate (GstFFMpegVidDec * ffmpegdec, gboolean force)
+{
+  GstVideoFormat fmt;
+  GstVideoInfo *in_info, *out_info;
+  GstVideoCodecState *output_state;
+  gint fps_n, fps_d;
+
+  if (!update_video_context (ffmpegdec, force))
+    return TRUE;
+
+  fmt = gst_ffmpeg_pixfmt_to_videoformat (ffmpegdec->ctx_pix_fmt);
   if (G_UNLIKELY (fmt == GST_VIDEO_FORMAT_UNKNOWN))
     goto unknown_format;
 
-  output_format =
+  output_state =
       gst_video_decoder_set_output_state (GST_VIDEO_DECODER (ffmpegdec), fmt,
-      ffmpegdec->context->width, ffmpegdec->context->height,
-      ffmpegdec->input_state);
-  if (context->sample_aspect_ratio.num) {
-    GST_VIDEO_INFO_PAR_N (&output_format->info) =
-        context->sample_aspect_ratio.num;
-    GST_VIDEO_INFO_PAR_D (&output_format->info) =
-        context->sample_aspect_ratio.den;
-  }
+      ffmpegdec->ctx_width, ffmpegdec->ctx_height, ffmpegdec->input_state);
   if (ffmpegdec->output_state)
     gst_video_codec_state_unref (ffmpegdec->output_state);
-  ffmpegdec->output_state = output_format;
+  ffmpegdec->output_state = output_state;
+
+  in_info = &ffmpegdec->input_state->info;
+  out_info = &ffmpegdec->output_state->info;
+
+  /* set the interlaced flag */
+  if (ffmpegdec->ctx_interlaced)
+    out_info->interlace_mode = GST_VIDEO_INTERLACE_MODE_MIXED;
+  else
+    out_info->interlace_mode = GST_VIDEO_INTERLACE_MODE_PROGRESSIVE;
+
+  /* try to find a good framerate */
+  if (in_info->fps_d) {
+    /* take framerate from input when it was specified (#313970) */
+    fps_n = in_info->fps_n;
+    fps_d = in_info->fps_d;
+  } else {
+    fps_n = ffmpegdec->ctx_time_d / ffmpegdec->ctx_ticks;
+    fps_d = ffmpegdec->ctx_time_n;
+
+    if (!fps_d) {
+      GST_LOG_OBJECT (ffmpegdec, "invalid framerate: %d/0, -> %d/1", fps_n,
+          fps_n);
+      fps_d = 1;
+    }
+    if (gst_util_fraction_compare (fps_n, fps_d, 1000, 1) > 0) {
+      GST_LOG_OBJECT (ffmpegdec, "excessive framerate: %d/%d, -> 0/1", fps_n,
+          fps_d);
+      fps_n = 0;
+      fps_d = 1;
+    }
+  }
+  GST_LOG_OBJECT (ffmpegdec, "setting framerate: %d/%d", fps_n, fps_d);
+  out_info->fps_n = fps_n;
+  out_info->fps_d = fps_d;
+
+  /* calculate and update par now */
+  gst_ffmpegviddec_update_par (ffmpegdec, in_info, out_info);
 
   return TRUE;
 
@@ -720,7 +852,7 @@ unknown_format:
  *
  * Sets the skip_frame flag and if things are really bad, skips to the next
  * keyframe.
- * 
+ *
  * Returns TRUE if the frame should be decoded, FALSE if the frame can be dropped
  * entirely.
  */
@@ -1017,21 +1149,13 @@ gst_ffmpegviddec_video_frame (GstFFMpegVidDec * ffmpegdec,
   GST_DEBUG_OBJECT (ffmpegdec, "repeat_pict:%d",
       ffmpegdec->picture->repeat_pict);
   GST_DEBUG_OBJECT (ffmpegdec, "interlaced_frame:%d (current:%d)",
-      ffmpegdec->picture->interlaced_frame,
-      GST_VIDEO_INFO_IS_INTERLACED (&ffmpegdec->input_state->info));
+      ffmpegdec->picture->interlaced_frame, ffmpegdec->ctx_interlaced);
 
-  if (G_UNLIKELY (ffmpegdec->input_state
-          && ffmpegdec->picture->interlaced_frame !=
-          GST_VIDEO_INFO_IS_INTERLACED (&ffmpegdec->input_state->info))) {
+  if (G_UNLIKELY (ffmpegdec->picture->interlaced_frame !=
+          ffmpegdec->ctx_interlaced)) {
     GST_WARNING ("Change in interlacing ! picture:%d, recorded:%d",
-        ffmpegdec->picture->interlaced_frame,
-        GST_VIDEO_INFO_IS_INTERLACED (&ffmpegdec->input_state->info));
-    if (ffmpegdec->picture->interlaced_frame)
-      GST_VIDEO_INFO_INTERLACE_MODE (&ffmpegdec->input_state->info) =
-          GST_VIDEO_INTERLACE_MODE_INTERLEAVED;
-    else
-      GST_VIDEO_INFO_INTERLACE_MODE (&ffmpegdec->input_state->info) =
-          GST_VIDEO_INTERLACE_MODE_PROGRESSIVE;
+        ffmpegdec->picture->interlaced_frame, ffmpegdec->ctx_interlaced);
+    ffmpegdec->ctx_interlaced = ffmpegdec->picture->interlaced_frame;
     if (!gst_ffmpegviddec_negotiate (ffmpegdec, TRUE))
       goto negotiation_error;
   }
@@ -1042,22 +1166,6 @@ gst_ffmpegviddec_video_frame (GstFFMpegVidDec * ffmpegdec,
   if (G_UNLIKELY (*ret != GST_FLOW_OK))
     goto no_output;
 
-  if (G_UNLIKELY (ffmpegdec->input_state
-          && ffmpegdec->picture->interlaced_frame !=
-          GST_VIDEO_INFO_IS_INTERLACED (&ffmpegdec->input_state->info))) {
-    GST_WARNING ("Change in interlacing ! picture:%d, recorded:%d",
-        ffmpegdec->picture->interlaced_frame,
-        GST_VIDEO_INFO_IS_INTERLACED (&ffmpegdec->input_state->info));
-    if (ffmpegdec->picture->interlaced_frame)
-      GST_VIDEO_INFO_INTERLACE_MODE (&ffmpegdec->input_state->info) =
-          GST_VIDEO_INTERLACE_MODE_INTERLEAVED;
-    else
-      GST_VIDEO_INFO_INTERLACE_MODE (&ffmpegdec->input_state->info) =
-          GST_VIDEO_INTERLACE_MODE_PROGRESSIVE;
-    if (!gst_ffmpegviddec_negotiate (ffmpegdec, TRUE))
-      goto negotiation_error;
-  }
-
   /* check if we are dealing with a keyframe here, this will also check if we
    * are dealing with B frames. */
   iskeyframe = check_keyframe (ffmpegdec);
@@ -1417,8 +1525,8 @@ gst_ffmpegviddec_decide_allocation (GstVideoDecoder * decoder, GstQuery * query)
     avcodec_align_dimensions2 (ffmpegdec->context, &width, &height,
         linesize_align);
     edge =
-        ffmpegdec->
-        context->flags & CODEC_FLAG_EMU_EDGE ? 0 : avcodec_get_edge_width ();
+        ffmpegdec->context->
+        flags & CODEC_FLAG_EMU_EDGE ? 0 : avcodec_get_edge_width ();
     /* increase the size for the padding */
     width += edge << 1;
     height += edge << 1;