[FFmpeg-devel] [PATCH, v3 2/3] fftools/ffmpeg: support variable resolution encode

[Linjie Fu]

Flush encoders when resolution change happens.

Use AV_CODEC_CAP_PARAM_CHANGE flag for encoder to indicate whether
it supports variable/dynamic resolution encoding.

Signed-off-by: Linjie Fu <linjie.fu at intel.com>
---
[v3]: use AV_CODEC_CAP_PARAM_CHANGE flag
 fftools/ffmpeg.c    | 14 ++++++++++++++
 libavcodec/rawenc.c |  1 +
 2 files changed, 15 insertions(+)

diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index 5d52430..35b0f89 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -130,6 +130,7 @@ static void do_video_stats(OutputStream *ost, int frame_size);
 static BenchmarkTimeStamps get_benchmark_time_stamps(void);
 static int64_t getmaxrss(void);
 static int ifilter_has_all_input_formats(FilterGraph *fg);
+static void flush_encoders(void);
 
 static int run_as_daemon  = 0;
 static int nb_frames_dup = 0;
@@ -1067,6 +1068,19 @@ static void do_video_out(OutputFile *of,
     InputStream *ist = NULL;
     AVFilterContext *filter = ost->filter->filter;
 
+    /* flush encoders in dynamic resolution encode */
+    if (next_picture && (enc->width != next_picture->width ||
+                         enc->height != next_picture->height)) {
+        flush_encoders();
+        avcodec_flush_buffers(enc);
+
+        if (!(enc->codec->capabilities & AV_CODEC_CAP_PARAM_CHANGE)) {
+            av_log(NULL, AV_LOG_ERROR, "Dynamic resolution encode "
+                            "is not supported by %s.\n", enc->codec->name);
+            goto error;
+        }
+    }
+
     if (ost->source_index >= 0)
         ist = input_streams[ost->source_index];
 
diff --git a/libavcodec/rawenc.c b/libavcodec/rawenc.c
index d181b74..9e8cb57 100644
--- a/libavcodec/rawenc.c
+++ b/libavcodec/rawenc.c
@@ -92,4 +92,5 @@ AVCodec ff_rawvideo_encoder = {
     .id             = AV_CODEC_ID_RAWVIDEO,
     .init           = raw_encode_init,
     .encode2        = raw_encode,
+    .capabilities   = AV_CODEC_CAP_PARAM_CHANGE,
 };
-- 
2.7.4