C# - ffmpeg(FFmpeg.AutoGen)를 이용한 remuxing.c 예제 포팅

지난 글에 이어,

C# - ffmpeg(FFmpeg.AutoGen)를 이용한 http_multiclient.c 예제 포팅
; https://www.sysnet.pe.kr/2/0/13002

using FFmpeg.AutoGen;
using FFmpeg.AutoGen.Example;
using System;
using System.IO;

namespace remuxing
{
    internal unsafe class Program
    {
        static unsafe void log_packet(AVFormatContext* fmt_ctx, AVPacket* pkt, string tag)
        {
            AVRational* time_base = &fmt_ctx->streams[pkt->stream_index]->time_base;

            Console.WriteLine($"{tag}: pts:{FFmpegHelper.av_ts2str(pkt->pts)} pts_time:{FFmpegHelper.av_ts2timestr(pkt->pts, time_base)}"
                + $" dts:{FFmpegHelper.av_ts2str(pkt->dts)} dts_time:{FFmpegHelper.av_ts2timestr(pkt->dts, time_base)}"
                + $" duration:{FFmpegHelper.av_ts2str(pkt->duration)} duration_time:{FFmpegHelper.av_ts2timestr(pkt->duration, time_base)}"
                + $" stream_index: {pkt->stream_index}");
        }

        static unsafe int Main(string[] args)
        {
            FFmpegBinariesHelper.RegisterFFmpegBinaries();

            AVOutputFormat* ofmt = null;
            AVFormatContext* ifmt_ctx = null;
            AVFormatContext* ofmt_ctx = null;
            AVPacket* pkt = null;
            string in_filename, out_filename;
            int ret, i;
            int stream_index = 0;
            int* stream_mapping = null;
            int stream_mapping_size = 0;

            string dirPath = Path.GetDirectoryName(typeof(Program).Assembly.Location) ?? "";
            string filename = "sample-10s.mp4";
            in_filename = Path.Combine(dirPath, "..", "..", "..", "Samples", filename);
            out_filename = Path.Combine(dirPath, Path.ChangeExtension(filename, "mkv"));

            pkt = ffmpeg.av_packet_alloc();
            if (pkt == null)
            {
                Console.WriteLine("Could not allocate AVPacket");
                return 1;
            }

            if ((ret = ffmpeg.avformat_open_input(&ifmt_ctx, in_filename, null, null)) < 0)
            {
                Console.WriteLine($"Could not open input fiel '{in_filename}'");
                goto end;
            }

            if ((ret = ffmpeg.avformat_find_stream_info(ifmt_ctx, null)) < 0)
            {
                Console.WriteLine("Failed to retrieve input stream information");
                goto end;
            }

            ffmpeg.av_dump_format(ifmt_ctx, 0, in_filename, 0);

            ffmpeg.avformat_alloc_output_context2(&ofmt_ctx, null, null, out_filename);
            if (ofmt_ctx == null)
            {
                Console.WriteLine("Could not create output context");
                ret = ffmpeg.AVERROR_UNKNOWN;
                goto end;
            }

            stream_mapping_size = (int)ifmt_ctx->nb_streams;
            stream_mapping = (int *)ffmpeg.av_calloc((ulong)stream_mapping_size, 4);
            if (stream_mapping == null)
            {
                ret = ffmpeg.AVERROR(ffmpeg.ENOMEM);
                goto end;
            }

            ofmt = ofmt_ctx->oformat;

            for (i = 0; i < ifmt_ctx->nb_streams; i ++)
            {
                AVStream* out_stream;
                AVStream* in_stream = ifmt_ctx->streams[i];
                AVCodecParameters* in_codecpar = in_stream->codecpar;

                if (in_codecpar->codec_type != AVMediaType.AVMEDIA_TYPE_AUDIO &&
                    in_codecpar->codec_type != AVMediaType.AVMEDIA_TYPE_VIDEO &&
                    in_codecpar->codec_type != AVMediaType.AVMEDIA_TYPE_SUBTITLE)
                {
                    stream_mapping[i] = -1;
                    continue;
                }

                stream_mapping[i] = stream_index++;

                out_stream = ffmpeg.avformat_new_stream(ofmt_ctx, null);
                if (out_stream == null)
                {
                    Console.WriteLine("Failed allocating output stream");
                    ret = ffmpeg.AVERROR_UNKNOWN;
                    goto end;
                }

                ret = ffmpeg.avcodec_parameters_copy(out_stream->codecpar, in_codecpar);
                if (ret < 0)
                {
                    Console.WriteLine("Failed to copy codec parameters");
                    goto end;
                }

                out_stream->codecpar->codec_tag = 0;
            }

            ffmpeg.av_dump_format(ofmt_ctx, 0, out_filename, 1);

            if ((ofmt->flags & ffmpeg.AVFMT_NOFILE) == 0)
            {
                ret = ffmpeg.avio_open(&ofmt_ctx->pb, out_filename, ffmpeg.AVIO_FLAG_WRITE);
                if (ret < 0)
                {
                    Console.WriteLine($"Could not open output file '{out_filename}");
                    goto end;
                }
            }

            ret = ffmpeg.avformat_write_header(ofmt_ctx, null);
            if (ret < 0)
            {
                Console.WriteLine("Error occurred when opening output file");
                goto end;
            }

            while (true)
            {
                AVStream* in_stream;
                AVStream* out_stream;

                ret = ffmpeg.av_read_frame(ifmt_ctx, pkt);
                if (ret < 0)
                {
                    break;
                }

                in_stream = ifmt_ctx->streams[pkt->stream_index];
                if (pkt->stream_index >= stream_mapping_size || stream_mapping[pkt->stream_index] < 0)
                {
                    ffmpeg.av_packet_unref(pkt);
                    continue;
                }

                pkt->stream_index = stream_mapping[pkt->stream_index];
                out_stream = ofmt_ctx->streams[pkt->stream_index];
                log_packet(ifmt_ctx, pkt, "in");

                ffmpeg.av_packet_rescale_ts(pkt, in_stream->time_base, out_stream->time_base);
                pkt->pos = -1;
                log_packet(ofmt_ctx, pkt, "out");

                ret = ffmpeg.av_interleaved_write_frame(ofmt_ctx, pkt);
                if (ret < 0)
                {
                    Console.WriteLine("Error muxing packet");
                    break;
                }
            }

            ffmpeg.av_write_trailer(ofmt_ctx);

        end:
            ffmpeg.av_packet_free(&pkt);
            ffmpeg.avformat_close_input(&ifmt_ctx);

            if (ofmt_ctx != null && (ofmt->flags & ffmpeg.AVFMT_NOFILE) == 0)
            {
                ffmpeg.avio_closep(&ofmt_ctx->pb);
            }

            ffmpeg.avformat_free_context(ofmt_ctx);

            ffmpeg.av_freep(&stream_mapping);

            if (ret < 0 && ret != ffmpeg.AVERROR_EOF)
            {
                Console.WriteLine($"Error occurred: {FFmpegHelper.av_err2str(ret)}");
                return 1;
            }

            return 0;
        }
    }
}

avi: 
    H.264 bitstream malformed, no startcode found, use the video bitstream filter 'h264_mp4toannexb' to fix it ('-bsf:v h264_mp4toannexb' option with ffmpeg)
    Error muxing packet
    Error occurred: Invalid data found when processing input

vob:
    [svcd @ 000001ecb820b380] VBV buffer size not set, using default size of 230KB
    If you want the mpeg file to be compliant to some specification
    Like DVD, VCD or others, make sure you set the correct buffer size
    [svcd @ 000001ecb820b380] Unsupported audio codec.Must be one of mp1, mp2, mp3, 16 - bit pcm_dvd, pcm_s16be, ac3 or dts.
    Error occurred when opening output file
    Error occurred: Invalid argument

mpeg: 
    [mpeg @ 0000020de269b380] VBV buffer size not set, using default size of 230KB
    If you want the mpeg file to be compliant to some specification
    Like DVD, VCD or others, make sure you set the correct buffer size
    [mpeg @ 0000020de269b380] Unsupported audio codec.Must be one of mp1, mp2, mp3, 16 - bit pcm_dvd, pcm_s16be, ac3 or dts.
    Error occurred when opening output file
    Error occurred: Invalid argument

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '...[생략]...\..\..\..\Samples\sample-10s.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.44.100
  Duration: 00:00:10.24, start: 0.000000, bitrate: 4285 kb/s
  Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], 4207 kb/s, 29.97 fps, 29.97 tbr, 30k tbn (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 121 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]
Output #0, mov, to '...[생략]...\sample-10s.mov':
  Stream #0:0: Video: h264 (High), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 4207 kb/s
  Stream #0:1: Audio: aac (LC), 44100 Hz, stereo, fltp, 121 kb/s
in: pts:0 pts_time:NOPTS dts:-2002 dts_time:-0.0667333 duration:1001 duration_time:0.0333667 stream_index: 0
out: pts:0 pts_time:NOPTS dts:-6006 dts_time:-0.0667333 duration:3003 duration_time:0.0333667 stream_index: 0
in: pts:4004 pts_time:0.133467 dts:-1001 dts_time:-0.0333667 duration:1001 duration_time:0.0333667 stream_index: 0
out: pts:12012 pts_time:0.133467 dts:-3003 dts_time:-0.0333667 duration:3003 duration_time:0.0333667 stream_index: 0
...[생략]...
out: pts:448512 pts_time:10.1703 dts:448512 dts_time:10.1703 duration:1024 duration_time:0.02322 stream_index: 1
in: pts:449536 pts_time:10.1936 dts:449536 dts_time:10.1936 duration:990 duration_time:0.022449 stream_index: 1
out: pts:449536 pts_time:10.1936 dts:449536 dts_time:10.1936 duration:990 duration_time:0.022449 stream_index: 1

C# - ffmpeg(FFmpeg.AutoGen)를 이용한 demuxing_decoding.c 예제 포팅
; https://www.sysnet.pe.kr/2/0/12987

C# - ffmpeg(FFmpeg.AutoGen)를 이용한 muxing.c 예제 포팅
; https://www.sysnet.pe.kr/2/0/12971