transcode_x264/
transcode-x264.rs

1// Given an input file, transcode all video streams into H.264 (using libx264)
2// while copying audio and subtitle streams.
3//
4// Invocation:
5//
6//   transcode-x264 <input> <output> [<x264_opts>]
7//
8// <x264_opts> is a comma-delimited list of key=val. default is "preset=medium".
9// See https://ffmpeg.org/ffmpeg-codecs.html#libx264_002c-libx264rgb and
10// https://trac.ffmpeg.org/wiki/Encode/H.264 for available and commonly used
11// options.
12//
13// Examples:
14//
15//   transcode-x264 input.flv output.mp4
16//   transcode-x264 input.mkv output.mkv 'preset=veryslow,crf=18'
17
18extern crate ffmpeg_next as ffmpeg;
19
20use std::collections::HashMap;
21use std::env;
22use std::time::Instant;
23
24use ffmpeg::{
25    codec, decoder, encoder, format, frame, log, media, picture, Dictionary, Packet, Rational,
26};
27
28const DEFAULT_X264_OPTS: &str = "preset=medium";
29
30struct Transcoder {
31    ost_index: usize,
32    decoder: decoder::Video,
33    input_time_base: Rational,
34    encoder: encoder::Video,
35    logging_enabled: bool,
36    frame_count: usize,
37    last_log_frame_count: usize,
38    starting_time: Instant,
39    last_log_time: Instant,
40}
41
42impl Transcoder {
43    fn new(
44        ist: &format::stream::Stream,
45        octx: &mut format::context::Output,
46        ost_index: usize,
47        x264_opts: Dictionary,
48        enable_logging: bool,
49    ) -> Result<Self, ffmpeg::Error> {
50        let global_header = octx.format().flags().contains(format::Flags::GLOBAL_HEADER);
51        let decoder = ffmpeg::codec::context::Context::from_parameters(ist.parameters())?
52            .decoder()
53            .video()?;
54
55        let codec = encoder::find(codec::Id::H264);
56        let mut ost = octx.add_stream(codec)?;
57
58        let mut encoder =
59            codec::context::Context::new_with_codec(codec.ok_or(ffmpeg::Error::InvalidData)?)
60                .encoder()
61                .video()?;
62        ost.set_parameters(&encoder);
63        encoder.set_height(decoder.height());
64        encoder.set_width(decoder.width());
65        encoder.set_aspect_ratio(decoder.aspect_ratio());
66        encoder.set_format(decoder.format());
67        encoder.set_frame_rate(decoder.frame_rate());
68        encoder.set_time_base(ist.time_base());
69
70        if global_header {
71            encoder.set_flags(codec::Flags::GLOBAL_HEADER);
72        }
73
74        let opened_encoder = encoder
75            .open_with(x264_opts)
76            .expect("error opening x264 with supplied settings");
77        ost.set_parameters(&opened_encoder);
78        Ok(Self {
79            ost_index,
80            decoder,
81            input_time_base: ist.time_base(),
82            encoder: opened_encoder,
83            logging_enabled: enable_logging,
84            frame_count: 0,
85            last_log_frame_count: 0,
86            starting_time: Instant::now(),
87            last_log_time: Instant::now(),
88        })
89    }
90
91    fn send_packet_to_decoder(&mut self, packet: &Packet) {
92        self.decoder.send_packet(packet).unwrap();
93    }
94
95    fn send_eof_to_decoder(&mut self) {
96        self.decoder.send_eof().unwrap();
97    }
98
99    fn receive_and_process_decoded_frames(
100        &mut self,
101        octx: &mut format::context::Output,
102        ost_time_base: Rational,
103    ) {
104        let mut frame = frame::Video::empty();
105        while self.decoder.receive_frame(&mut frame).is_ok() {
106            self.frame_count += 1;
107            let timestamp = frame.timestamp();
108            self.log_progress(f64::from(
109                Rational(timestamp.unwrap_or(0) as i32, 1) * self.input_time_base,
110            ));
111            frame.set_pts(timestamp);
112            frame.set_kind(picture::Type::None);
113            self.send_frame_to_encoder(&frame);
114            self.receive_and_process_encoded_packets(octx, ost_time_base);
115        }
116    }
117
118    fn send_frame_to_encoder(&mut self, frame: &frame::Video) {
119        self.encoder.send_frame(frame).unwrap();
120    }
121
122    fn send_eof_to_encoder(&mut self) {
123        self.encoder.send_eof().unwrap();
124    }
125
126    fn receive_and_process_encoded_packets(
127        &mut self,
128        octx: &mut format::context::Output,
129        ost_time_base: Rational,
130    ) {
131        let mut encoded = Packet::empty();
132        while self.encoder.receive_packet(&mut encoded).is_ok() {
133            encoded.set_stream(self.ost_index);
134            encoded.rescale_ts(self.input_time_base, ost_time_base);
135            encoded.write_interleaved(octx).unwrap();
136        }
137    }
138
139    fn log_progress(&mut self, timestamp: f64) {
140        if !self.logging_enabled
141            || (self.frame_count - self.last_log_frame_count < 100
142                && self.last_log_time.elapsed().as_secs_f64() < 1.0)
143        {
144            return;
145        }
146        eprintln!(
147            "time elpased: \t{:8.2}\tframe count: {:8}\ttimestamp: {:8.2}",
148            self.starting_time.elapsed().as_secs_f64(),
149            self.frame_count,
150            timestamp
151        );
152        self.last_log_frame_count = self.frame_count;
153        self.last_log_time = Instant::now();
154    }
155}
156
157fn parse_opts<'a>(s: String) -> Option<Dictionary<'a>> {
158    let mut dict = Dictionary::new();
159    for keyval in s.split_terminator(',') {
160        let tokens: Vec<&str> = keyval.split('=').collect();
161        match tokens[..] {
162            [key, val] => dict.set(key, val),
163            _ => return None,
164        }
165    }
166    Some(dict)
167}
168
169fn main() {
170    let input_file = env::args().nth(1).expect("missing input file");
171    let output_file = env::args().nth(2).expect("missing output file");
172    let x264_opts = parse_opts(
173        env::args()
174            .nth(3)
175            .unwrap_or_else(|| DEFAULT_X264_OPTS.to_string()),
176    )
177    .expect("invalid x264 options string");
178
179    eprintln!("x264 options: {:?}", x264_opts);
180
181    ffmpeg::init().unwrap();
182    log::set_level(log::Level::Info);
183
184    let mut ictx = format::input(&input_file).unwrap();
185    let mut octx = format::output(&output_file).unwrap();
186
187    format::context::input::dump(&ictx, 0, Some(&input_file));
188
189    let best_video_stream_index = ictx
190        .streams()
191        .best(media::Type::Video)
192        .map(|stream| stream.index());
193    let mut stream_mapping: Vec<isize> = vec![0; ictx.nb_streams() as _];
194    let mut ist_time_bases = vec![Rational(0, 0); ictx.nb_streams() as _];
195    let mut ost_time_bases = vec![Rational(0, 0); ictx.nb_streams() as _];
196    let mut transcoders = HashMap::new();
197    let mut ost_index = 0;
198    for (ist_index, ist) in ictx.streams().enumerate() {
199        let ist_medium = ist.parameters().medium();
200        if ist_medium != media::Type::Audio
201            && ist_medium != media::Type::Video
202            && ist_medium != media::Type::Subtitle
203        {
204            stream_mapping[ist_index] = -1;
205            continue;
206        }
207        stream_mapping[ist_index] = ost_index;
208        ist_time_bases[ist_index] = ist.time_base();
209        if ist_medium == media::Type::Video {
210            // Initialize transcoder for video stream.
211            transcoders.insert(
212                ist_index,
213                Transcoder::new(
214                    &ist,
215                    &mut octx,
216                    ost_index as _,
217                    x264_opts.to_owned(),
218                    Some(ist_index) == best_video_stream_index,
219                )
220                .unwrap(),
221            );
222        } else {
223            // Set up for stream copy for non-video stream.
224            let mut ost = octx.add_stream(encoder::find(codec::Id::None)).unwrap();
225            ost.set_parameters(ist.parameters());
226            // We need to set codec_tag to 0 lest we run into incompatible codec tag
227            // issues when muxing into a different container format. Unfortunately
228            // there's no high level API to do this (yet).
229            unsafe {
230                (*ost.parameters().as_mut_ptr()).codec_tag = 0;
231            }
232        }
233        ost_index += 1;
234    }
235
236    octx.set_metadata(ictx.metadata().to_owned());
237    format::context::output::dump(&octx, 0, Some(&output_file));
238    octx.write_header().unwrap();
239
240    for (ost_index, _) in octx.streams().enumerate() {
241        ost_time_bases[ost_index] = octx.stream(ost_index as _).unwrap().time_base();
242    }
243
244    for (stream, mut packet) in ictx.packets() {
245        let ist_index = stream.index();
246        let ost_index = stream_mapping[ist_index];
247        if ost_index < 0 {
248            continue;
249        }
250        let ost_time_base = ost_time_bases[ost_index as usize];
251        match transcoders.get_mut(&ist_index) {
252            Some(transcoder) => {
253                transcoder.send_packet_to_decoder(&packet);
254                transcoder.receive_and_process_decoded_frames(&mut octx, ost_time_base);
255            }
256            None => {
257                // Do stream copy on non-video streams.
258                packet.rescale_ts(ist_time_bases[ist_index], ost_time_base);
259                packet.set_position(-1);
260                packet.set_stream(ost_index as _);
261                packet.write_interleaved(&mut octx).unwrap();
262            }
263        }
264    }
265
266    // Flush encoders and decoders.
267    for (ost_index, transcoder) in transcoders.iter_mut() {
268        let ost_time_base = ost_time_bases[*ost_index];
269        transcoder.send_eof_to_decoder();
270        transcoder.receive_and_process_decoded_frames(&mut octx, ost_time_base);
271        transcoder.send_eof_to_encoder();
272        transcoder.receive_and_process_encoded_packets(&mut octx, ost_time_base);
273    }
274
275    octx.write_trailer().unwrap();
276}
transcode_x264/transcode-x264.rs

transcode_x264/
transcode-x264.rs
