doc/examples/transcoding is not able to reencode with libx264. Please help to teach it to do so.
This script reproduces the issue in automated fashion: https://gist.github.com/andrey-utkin/925ce227b2b530d1e808 (ffmpeg.issue.sh attached). The script applies one patch to the example program. The patch addresses a bit different issue but is required to proceed with this usecase. (7e12ed3c07e38d49b3aa025897a222a92fbaf3a5.patch attached.) JEEB on IRC asked to try both static and shared builds, so the script builds and runs both. Here you can see what actually happens (what is the problem): https://gist.github.com/andrey-utkin/c72034b68f7950101dbc https://gist.github.com/andrey-utkin/9994afa6dd26627cee50 (to prove that input pixel format doesn't change anything). Quoting actual output exposing the problem here. See "broken ffmpeg default settings detected". $ for x in /tmp/ffmpeg.{static,shared} > do > pushd $x > export LD_LIBRARY_PATH="$x/lib" > ./bin/ffmpeg -f lavfi -i testsrc -t 1 -c:v libx264 -y test.mkv > ./transcoding test.mkv out.mkv || true # this fails > popd > done /tmp/ffmpeg.static /tmp ffmpeg version N-78232-g9962718 Copyright (c) 2000-2016 the FFmpeg developers built with gcc 5.3.0 (Gentoo 5.3.0 p1.0, pie-0.6.5) configuration: --enable-libx264 --enable-gpl --prefix=/tmp/ffmpeg.static libavutil 55. 16.101 / 55. 16.101 libavcodec 57. 24.101 / 57. 24.101 libavformat 57. 23.101 / 57. 23.101 libavdevice 57. 0.101 / 57. 0.101 libavfilter 6. 27.100 / 6. 27.100 libswscale 4. 0.100 / 4. 0.100 libswresample 2. 0.101 / 2. 0.101 libpostproc 54. 0.100 / 54. 0.100 Input #0, lavfi, from 'testsrc': Duration: N/A, start: 0.000000, bitrate: N/A Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 320x240 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc No pixel format specified, yuv444p for H.264 encoding chosen. Use -pix_fmt yuv420p for compatibility with outdated media players. [libx264 @ 0x35024e0] using SAR=1/1 [libx264 @ 0x35024e0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX [libx264 @ 0x35024e0] profile High 4:4:4 Predictive, level 1.3, 4:4:4 8-bit [libx264 @ 0x35024e0] 264 - core 148 r2665M a01e339 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=4 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00 Output #0, matroska, to 'test.mkv': Metadata: encoder : Lavf57.23.101 Stream #0:0: Video: h264 (libx264) (H264 / 0x34363248), yuv444p, 320x240 [SAR 1:1 DAR 4:3], q=-1--1, 25 fps, 1k tbn, 25 tbc Metadata: encoder : Lavc57.24.101 libx264 Side data: unknown side data type 10 (24 bytes) Stream mapping: Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264)) Press [q] to stop, [?] for help frame= 25 fps=0.0 q=-1.0 Lsize= 8kB time=00:00:00.92 bitrate= 74.0kbits/s speed=13.6x video:7kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 11.975260% [libx264 @ 0x35024e0] frame I:1 Avg QP:19.50 size: 2846 [libx264 @ 0x35024e0] frame P:9 Avg QP:17.62 size: 346 [libx264 @ 0x35024e0] frame B:15 Avg QP:14.18 size: 64 [libx264 @ 0x35024e0] consecutive B-frames: 20.0% 0.0% 0.0% 80.0% [libx264 @ 0x35024e0] mb I I16..4: 31.3% 41.7% 27.0% [libx264 @ 0x35024e0] mb P I16..4: 1.2% 2.0% 0.6% P16..4: 8.6% 3.3% 2.0% 0.0% 0.0% skip:82.2% [libx264 @ 0x35024e0] mb B I16..4: 0.2% 0.1% 0.0% B16..8: 4.8% 0.1% 0.0% direct: 0.2% skip:94.5% L0:39.7% L1:54.9% BI: 5.4% [libx264 @ 0x35024e0] 8x8 transform intra:44.1% inter:48.9% [libx264 @ 0x35024e0] coded y,u,v intra: 12.2% 11.2% 11.0% inter: 0.7% 0.9% 0.8% [libx264 @ 0x35024e0] i16 v,h,dc,p: 71% 19% 3% 7% [libx264 @ 0x35024e0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 71% 6% 23% 0% 0% 0% 0% 0% 0% [libx264 @ 0x35024e0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 47% 31% 15% 2% 1% 1% 0% 2% 0% [libx264 @ 0x35024e0] Weighted P-Frames: Y:0.0% UV:0.0% [libx264 @ 0x35024e0] ref P L0: 63.4% 5.0% 23.5% 8.1% [libx264 @ 0x35024e0] ref B L0: 73.3% 23.3% 3.5% [libx264 @ 0x35024e0] ref B L1: 97.8% 2.2% [libx264 @ 0x35024e0] kb/s:55.28 Input #0, matroska,webm, from 'test.mkv': Metadata: ENCODER : Lavf57.23.101 Duration: 00:00:01.00, start: 0.000000, bitrate: 68 kb/s Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv444p, 320x240 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 1k tbn, 50 tbc (default) Metadata: ENCODER : Lavc57.24.101 libx264 DURATION : 00:00:01.000000000 [libx264 @ 0x20b8b40] broken ffmpeg default settings detected [libx264 @ 0x20b8b40] use an encoding preset (e.g. -vpre medium) [libx264 @ 0x20b8b40] preset usage: -vpre <speed> -vpre <profile> [libx264 @ 0x20b8b40] speed presets are listed in x264 --help [libx264 @ 0x20b8b40] profile is optional; x264 defaults to high Cannot open video encoder for stream #0 Error occurred: Generic error in an external library /tmp /tmp/ffmpeg.shared /tmp ffmpeg version N-78232-g9962718 Copyright (c) 2000-2016 the FFmpeg developers built with gcc 5.3.0 (Gentoo 5.3.0 p1.0, pie-0.6.5) configuration: --enable-libx264 --enable-gpl --prefix=/tmp/ffmpeg.shared --enable-shared libavutil 55. 16.101 / 55. 16.101 libavcodec 57. 24.101 / 57. 24.101 libavformat 57. 23.101 / 57. 23.101 libavdevice 57. 0.101 / 57. 0.101 libavfilter 6. 27.100 / 6. 27.100 libswscale 4. 0.100 / 4. 0.100 libswresample 2. 0.101 / 2. 0.101 libpostproc 54. 0.100 / 54. 0.100 Input #0, lavfi, from 'testsrc': Duration: N/A, start: 0.000000, bitrate: N/A Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 320x240 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc No pixel format specified, yuv444p for H.264 encoding chosen. Use -pix_fmt yuv420p for compatibility with outdated media players. [libx264 @ 0x10394e0] using SAR=1/1 [libx264 @ 0x10394e0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX [libx264 @ 0x10394e0] profile High 4:4:4 Predictive, level 1.3, 4:4:4 8-bit [libx264 @ 0x10394e0] 264 - core 148 r2665M a01e339 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=4 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00 Output #0, matroska, to 'test.mkv': Metadata: encoder : Lavf57.23.101 Stream #0:0: Video: h264 (libx264) (H264 / 0x34363248), yuv444p, 320x240 [SAR 1:1 DAR 4:3], q=-1--1, 25 fps, 1k tbn, 25 tbc Metadata: encoder : Lavc57.24.101 libx264 Side data: unknown side data type 10 (24 bytes) Stream mapping: Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264)) Press [q] to stop, [?] for help frame= 25 fps=0.0 q=-1.0 Lsize= 8kB time=00:00:00.92 bitrate= 74.0kbits/s speed=17.1x video:7kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 11.975260% [libx264 @ 0x10394e0] frame I:1 Avg QP:19.50 size: 2846 [libx264 @ 0x10394e0] frame P:9 Avg QP:17.62 size: 346 [libx264 @ 0x10394e0] frame B:15 Avg QP:14.18 size: 64 [libx264 @ 0x10394e0] consecutive B-frames: 20.0% 0.0% 0.0% 80.0% [libx264 @ 0x10394e0] mb I I16..4: 31.3% 41.7% 27.0% [libx264 @ 0x10394e0] mb P I16..4: 1.2% 2.0% 0.6% P16..4: 8.6% 3.3% 2.0% 0.0% 0.0% skip:82.2% [libx264 @ 0x10394e0] mb B I16..4: 0.2% 0.1% 0.0% B16..8: 4.8% 0.1% 0.0% direct: 0.2% skip:94.5% L0:39.7% L1:54.9% BI: 5.4% [libx264 @ 0x10394e0] 8x8 transform intra:44.1% inter:48.9% [libx264 @ 0x10394e0] coded y,u,v intra: 12.2% 11.2% 11.0% inter: 0.7% 0.9% 0.8% [libx264 @ 0x10394e0] i16 v,h,dc,p: 71% 19% 3% 7% [libx264 @ 0x10394e0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 71% 6% 23% 0% 0% 0% 0% 0% 0% [libx264 @ 0x10394e0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 47% 31% 15% 2% 1% 1% 0% 2% 0% [libx264 @ 0x10394e0] Weighted P-Frames: Y:0.0% UV:0.0% [libx264 @ 0x10394e0] ref P L0: 63.4% 5.0% 23.5% 8.1% [libx264 @ 0x10394e0] ref B L0: 73.3% 23.3% 3.5% [libx264 @ 0x10394e0] ref B L1: 97.8% 2.2% [libx264 @ 0x10394e0] kb/s:55.28 Input #0, matroska,webm, from 'test.mkv': Metadata: ENCODER : Lavf57.23.101 Duration: 00:00:01.00, start: 0.000000, bitrate: 68 kb/s Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv444p, 320x240 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 1k tbn, 50 tbc (default) Metadata: ENCODER : Lavc57.24.101 libx264 DURATION : 00:00:01.000000000 [libx264 @ 0x2701b40] broken ffmpeg default settings detected [libx264 @ 0x2701b40] use an encoding preset (e.g. -vpre medium) [libx264 @ 0x2701b40] preset usage: -vpre <speed> -vpre <profile> [libx264 @ 0x2701b40] speed presets are listed in x264 --help [libx264 @ 0x2701b40] profile is optional; x264 defaults to high Cannot open video encoder for stream #0 Error occurred: Generic error in an external library
ffmpeg.issue.sh
Description: application/shellscript
From 7e12ed3c07e38d49b3aa025897a222a92fbaf3a5 Mon Sep 17 00:00:00 2001
From: Andrey Utkin <andrey.ut...@pb.com>
Date: Mon, 1 Feb 2016 00:54:15 +0200
Subject: [PATCH] doc/example/transcoding: handle case of empty encoder
AVCodec.pix_fmts
---
doc/examples/transcoding.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/doc/examples/transcoding.c b/doc/examples/transcoding.c
index d5d410b..15fae4d 100644
--- a/doc/examples/transcoding.c
+++ b/doc/examples/transcoding.c
@@ -129,6 +129,9 @@ static int open_output_file(const char *filename)
enc_ctx->sample_aspect_ratio = dec_ctx->sample_aspect_ratio;
/* take first format from list of supported formats */
enc_ctx->pix_fmt = encoder->pix_fmts[0];
+ /* Below condition is true for libx264 */
+ if (enc_ctx->pix_fmt == AV_PIX_FMT_NONE)
+ enc_ctx->pix_fmt = dec_ctx->pix_fmt;
/* video time_base can be set to whatever is handy and supported by encoder */
enc_ctx->time_base = dec_ctx->time_base;
} else {
signature.asc
Description: OpenPGP digital signature
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
