Cleanup: move some stuff into process_video_frame().
[dcpomatic.git] / src / lib / ffmpeg_decoder.cc
index baec57f3d24e19473df2dd74788caa7a411e1841..f64ccbd3b6305249c4522ee69d175dee6bb26849 100644 (file)
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2018 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
 
 */
 
+
 /** @file  src/ffmpeg_decoder.cc
  *  @brief A decoder using FFmpeg to decode content.
  */
 
-#include "filter.h"
+
+#include "audio_buffers.h"
+#include "audio_content.h"
+#include "audio_decoder.h"
+#include "compose.hpp"
+#include "dcpomatic_log.h"
 #include "exceptions.h"
-#include "image.h"
-#include "util.h"
-#include "log.h"
-#include "ffmpeg_decoder.h"
-#include "subtitle_decoder.h"
 #include "ffmpeg_audio_stream.h"
-#include "ffmpeg_subtitle_stream.h"
-#include "video_filter_graph.h"
-#include "audio_buffers.h"
 #include "ffmpeg_content.h"
+#include "ffmpeg_decoder.h"
+#include "ffmpeg_subtitle_stream.h"
+#include "film.h"
+#include "filter.h"
+#include "frame_interval_checker.h"
+#include "image.h"
+#include "log.h"
 #include "raw_image_proxy.h"
+#include "text_content.h"
+#include "text_decoder.h"
+#include "util.h"
 #include "video_decoder.h"
-#include "film.h"
-#include "audio_decoder.h"
-#include "compose.hpp"
-#include "subtitle_content.h"
-#include "audio_content.h"
+#include "video_filter_graph.h"
 #include <dcp/subtitle_string.h>
 #include <sub/ssa_reader.h>
 #include <sub/subtitle.h>
@@ -49,78 +53,134 @@ extern "C" {
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 }
-#include <boost/foreach.hpp>
 #include <boost/algorithm/string.hpp>
-#include <vector>
 #include <iomanip>
 #include <iostream>
+#include <vector>
 #include <stdint.h>
 
 #include "i18n.h"
 
-#define LOG_GENERAL(...) _log->log (String::compose (__VA_ARGS__), LogEntry::TYPE_GENERAL);
-#define LOG_ERROR(...) _log->log (String::compose (__VA_ARGS__), LogEntry::TYPE_ERROR);
-#define LOG_WARNING_NC(...) _log->log (__VA_ARGS__, LogEntry::TYPE_WARNING);
-#define LOG_WARNING(...) _log->log (String::compose (__VA_ARGS__), LogEntry::TYPE_WARNING);
 
 using std::cout;
+using std::dynamic_pointer_cast;
+using std::make_shared;
+using std::min;
+using std::shared_ptr;
 using std::string;
 using std::vector;
-using std::list;
-using std::min;
-using std::pair;
-using std::max;
-using std::map;
-using boost::shared_ptr;
-using boost::is_any_of;
-using boost::split;
 using boost::optional;
-using boost::dynamic_pointer_cast;
 using dcp::Size;
+using namespace dcpomatic;
 
-FFmpegDecoder::FFmpegDecoder (shared_ptr<const FFmpegContent> c, shared_ptr<Log> log)
+
+FFmpegDecoder::FFmpegDecoder (shared_ptr<const Film> film, shared_ptr<const FFmpegContent> c, bool fast)
        : FFmpeg (c)
-       , _log (log)
-       , _have_current_subtitle (false)
+       , Decoder (film)
 {
-       if (c->video) {
-               video.reset (new VideoDecoder (this, c, log));
-               _pts_offset = pts_offset (c->ffmpeg_audio_streams(), c->first_video(), c->active_video_frame_rate());
+       if (c->video && c->video->use()) {
+               video = make_shared<VideoDecoder>(this, c);
+               _pts_offset = pts_offset (c->ffmpeg_audio_streams(), c->first_video(), c->active_video_frame_rate(film));
+               /* It doesn't matter what size or pixel format this is, it just needs to be black */
+               _black_image = make_shared<Image>(AV_PIX_FMT_RGB24, dcp::Size (128, 128), Image::Alignment::PADDED);
+               _black_image->make_black ();
        } else {
-               _pts_offset = ContentTime ();
+               _pts_offset = {};
        }
 
        if (c->audio) {
-               audio.reset (new AudioDecoder (this, c->audio, log));
+               audio = make_shared<AudioDecoder>(this, c->audio, fast);
        }
 
-       if (c->subtitle) {
-               subtitle.reset (new SubtitleDecoder (this, c->subtitle, log));
+       if (c->only_text()) {
+               /* XXX: this time here should be the time of the first subtitle, not 0 */
+               text.push_back (make_shared<TextDecoder>(this, c->only_text(), ContentTime()));
+       }
+
+       for (auto i: c->ffmpeg_audio_streams()) {
+               _next_time[i] = boost::optional<dcpomatic::ContentTime>();
        }
 }
 
-void
+
+bool
 FFmpegDecoder::flush ()
 {
-       /* Get any remaining frames */
+       /* Flush video and audio once */
+
+       bool did_something = false;
+       if (video) {
+               if (decode_and_process_video_packet(nullptr)) {
+                       did_something = true;
+               }
+       }
+
+       for (auto i: ffmpeg_content()->ffmpeg_audio_streams()) {
+               auto context = _codec_context[i->index(_format_context)];
+               int r = avcodec_send_packet (context, nullptr);
+               if (r < 0 && r != AVERROR_EOF) {
+                       /* EOF can happen if we've already sent a flush packet */
+                       throw DecodeError (N_("avcodec_send_packet"), N_("FFmpegDecoder::flush"), r);
+               }
+               r = avcodec_receive_frame (context, audio_frame(i));
+               if (r >= 0) {
+                       process_audio_frame (i);
+                       did_something = true;
+               }
+       }
 
-       _packet.data = 0;
-       _packet.size = 0;
+       if (did_something) {
+               /* We want to be called again */
+               return false;
+       }
 
-       /* XXX: should we reset _packet.data and size after each *_decode_* call? */
+       /* Make sure all streams are the same length and round up to the next video frame */
 
-       while (video && decode_video_packet ()) {}
+       auto const frc = film()->active_frame_rate_change(_ffmpeg_content->position());
+       ContentTime full_length (_ffmpeg_content->full_length(film()), frc);
+       full_length = full_length.ceil (frc.source);
+       if (video) {
+               double const vfr = _ffmpeg_content->video_frame_rate().get();
+               auto const f = full_length.frames_round (vfr);
+               auto v = video->position(film()).get_value_or(ContentTime()).frames_round(vfr) + 1;
+               while (v < f) {
+                       video->emit (film(), shared_ptr<const ImageProxy> (new RawImageProxy (_black_image)), v);
+                       ++v;
+               }
+       }
+
+       for (auto i: _ffmpeg_content->ffmpeg_audio_streams ()) {
+               auto a = audio->stream_position(film(), i);
+               /* Unfortunately if a is 0 that really means that we don't know the stream position since
+                  there has been no data on it since the last seek.  In this case we'll just do nothing
+                  here.  I'm not sure if that's the right idea.
+               */
+               if (a > ContentTime()) {
+                       while (a < full_length) {
+                               auto to_do = min (full_length - a, ContentTime::from_seconds (0.1));
+                               auto silence = make_shared<AudioBuffers>(i->channels(), to_do.frames_ceil (i->frame_rate()));
+                               silence->make_silent ();
+                               audio->emit (film(), i, silence, a, true);
+                               a += to_do;
+                       }
+               }
+       }
 
        if (audio) {
-               decode_audio_packet ();
                audio->flush ();
        }
+
+       return true;
 }
 
+
 bool
 FFmpegDecoder::pass ()
 {
-       int r = av_read_frame (_format_context, &_packet);
+       auto packet = av_packet_alloc();
+       DCPOMATIC_ASSERT (packet);
+
+       int r = av_read_frame (_format_context, packet);
 
        /* AVERROR_INVALIDDATA can apparently be returned sometimes even when av_read_frame
           has pretty-much succeeded (and hence generated data which should be processed).
@@ -134,57 +194,53 @@ FFmpegDecoder::pass ()
                        LOG_ERROR (N_("error on av_read_frame (%1) (%2)"), &buf[0], r);
                }
 
-               flush ();
-               return true;
+               av_packet_free (&packet);
+               return flush ();
        }
 
-       int const si = _packet.stream_index;
-       shared_ptr<const FFmpegContent> fc = _ffmpeg_content;
+       int const si = packet->stream_index;
+       auto fc = _ffmpeg_content;
 
-       if (_video_stream && si == _video_stream.get() && !video->ignore()) {
-               decode_video_packet ();
-       } else if (fc->subtitle_stream() && fc->subtitle_stream()->uses_index (_format_context, si)) {
-               decode_subtitle_packet ();
+       if (_video_stream && si == _video_stream.get() && video && !video->ignore()) {
+               decode_and_process_video_packet (packet);
+       } else if (fc->subtitle_stream() && fc->subtitle_stream()->uses_index(_format_context, si) && !only_text()->ignore()) {
+               decode_and_process_subtitle_packet (packet);
        } else {
-               decode_audio_packet ();
+               decode_and_process_audio_packet (packet);
        }
 
-       av_packet_unref (&_packet);
+       av_packet_free (&packet);
        return false;
 }
 
+
 /** @param data pointer to array of pointers to buffers.
  *  Only the first buffer will be used for non-planar data, otherwise there will be one per channel.
  */
 shared_ptr<AudioBuffers>
-FFmpegDecoder::deinterleave_audio (shared_ptr<FFmpegAudioStream> stream) const
+FFmpegDecoder::deinterleave_audio (AVFrame* frame)
 {
-       DCPOMATIC_ASSERT (bytes_per_audio_sample (stream));
+       auto format = static_cast<AVSampleFormat>(frame->format);
 
-       int const size = av_samples_get_buffer_size (
-               0, stream->stream(_format_context)->codec->channels, _frame->nb_samples, audio_sample_format (stream), 1
-               );
-
-       /* Deinterleave and convert to float */
+       /* XXX: can't we use swr_convert() to do the format conversion? */
 
-       /* total_samples and frames will be rounded down here, so if there are stray samples at the end
-          of the block that do not form a complete sample or frame they will be dropped.
-       */
-       int const total_samples = size / bytes_per_audio_sample (stream);
-       int const frames = total_samples / stream->channels();
-       shared_ptr<AudioBuffers> audio (new AudioBuffers (stream->channels(), frames));
+       int const channels = frame->channels;
+       int const frames = frame->nb_samples;
+       int const total_samples = frames * channels;
+       auto audio = make_shared<AudioBuffers>(channels, frames);
+       auto data = audio->data();
 
-       switch (audio_sample_format (stream)) {
+       switch (format) {
        case AV_SAMPLE_FMT_U8:
        {
-               uint8_t* p = reinterpret_cast<uint8_t *> (_frame->data[0]);
+               auto p = reinterpret_cast<uint8_t *> (frame->data[0]);
                int sample = 0;
                int channel = 0;
                for (int i = 0; i < total_samples; ++i) {
-                       audio->data(channel)[sample] = float(*p++) / (1 << 23);
+                       data[channel][sample] = float(*p++) / (1 << 23);
 
                        ++channel;
-                       if (channel == stream->channels()) {
+                       if (channel == channels) {
                                channel = 0;
                                ++sample;
                        }
@@ -194,14 +250,14 @@ FFmpegDecoder::deinterleave_audio (shared_ptr<FFmpegAudioStream> stream) const
 
        case AV_SAMPLE_FMT_S16:
        {
-               int16_t* p = reinterpret_cast<int16_t *> (_frame->data[0]);
+               auto p = reinterpret_cast<int16_t *> (frame->data[0]);
                int sample = 0;
                int channel = 0;
                for (int i = 0; i < total_samples; ++i) {
-                       audio->data(channel)[sample] = float(*p++) / (1 << 15);
+                       data[channel][sample] = float(*p++) / (1 << 15);
 
                        ++channel;
-                       if (channel == stream->channels()) {
+                       if (channel == channels) {
                                channel = 0;
                                ++sample;
                        }
@@ -211,10 +267,10 @@ FFmpegDecoder::deinterleave_audio (shared_ptr<FFmpegAudioStream> stream) const
 
        case AV_SAMPLE_FMT_S16P:
        {
-               int16_t** p = reinterpret_cast<int16_t **> (_frame->data);
-               for (int i = 0; i < stream->channels(); ++i) {
+               auto p = reinterpret_cast<int16_t **> (frame->data);
+               for (int i = 0; i < channels; ++i) {
                        for (int j = 0; j < frames; ++j) {
-                               audio->data(i)[j] = static_cast<float>(p[i][j]) / (1 << 15);
+                               data[i][j] = static_cast<float>(p[i][j]) / (1 << 15);
                        }
                }
        }
@@ -222,14 +278,14 @@ FFmpegDecoder::deinterleave_audio (shared_ptr<FFmpegAudioStream> stream) const
 
        case AV_SAMPLE_FMT_S32:
        {
-               int32_t* p = reinterpret_cast<int32_t *> (_frame->data[0]);
+               auto p = reinterpret_cast<int32_t *> (frame->data[0]);
                int sample = 0;
                int channel = 0;
                for (int i = 0; i < total_samples; ++i) {
-                       audio->data(channel)[sample] = static_cast<float>(*p++) / 2147483648;
+                       data[channel][sample] = static_cast<float>(*p++) / 2147483648;
 
                        ++channel;
-                       if (channel == stream->channels()) {
+                       if (channel == channels) {
                                channel = 0;
                                ++sample;
                        }
@@ -239,10 +295,10 @@ FFmpegDecoder::deinterleave_audio (shared_ptr<FFmpegAudioStream> stream) const
 
        case AV_SAMPLE_FMT_S32P:
        {
-               int32_t** p = reinterpret_cast<int32_t **> (_frame->data);
-               for (int i = 0; i < stream->channels(); ++i) {
+               auto p = reinterpret_cast<int32_t **> (frame->data);
+               for (int i = 0; i < channels; ++i) {
                        for (int j = 0; j < frames; ++j) {
-                               audio->data(i)[j] = static_cast<float>(p[i][j]) / 2147483648;
+                               data[i][j] = static_cast<float>(p[i][j]) / 2147483648;
                        }
                }
        }
@@ -250,14 +306,14 @@ FFmpegDecoder::deinterleave_audio (shared_ptr<FFmpegAudioStream> stream) const
 
        case AV_SAMPLE_FMT_FLT:
        {
-               float* p = reinterpret_cast<float*> (_frame->data[0]);
+               auto p = reinterpret_cast<float*> (frame->data[0]);
                int sample = 0;
                int channel = 0;
                for (int i = 0; i < total_samples; ++i) {
-                       audio->data(channel)[sample] = *p++;
+                       data[channel][sample] = *p++;
 
                        ++channel;
-                       if (channel == stream->channels()) {
+                       if (channel == channels) {
                                channel = 0;
                                ++sample;
                        }
@@ -267,36 +323,40 @@ FFmpegDecoder::deinterleave_audio (shared_ptr<FFmpegAudioStream> stream) const
 
        case AV_SAMPLE_FMT_FLTP:
        {
-               float** p = reinterpret_cast<float**> (_frame->data);
-               /* Sometimes there aren't as many channels in the _frame as in the stream */
-               for (int i = 0; i < _frame->channels; ++i) {
-                       memcpy (audio->data(i), p[i], frames * sizeof(float));
+               auto p = reinterpret_cast<float**> (frame->data);
+               DCPOMATIC_ASSERT (frame->channels <= channels);
+               /* Sometimes there aren't as many channels in the frame as in the stream */
+               for (int i = 0; i < frame->channels; ++i) {
+                       memcpy (data[i], p[i], frames * sizeof(float));
                }
-               for (int i = _frame->channels; i < stream->channels(); ++i) {
+               for (int i = frame->channels; i < channels; ++i) {
                        audio->make_silent (i);
                }
        }
        break;
 
        default:
-               throw DecodeError (String::compose (_("Unrecognised audio sample format (%1)"), static_cast<int> (audio_sample_format (stream))));
+               throw DecodeError (String::compose(_("Unrecognised audio sample format (%1)"), static_cast<int>(format)));
        }
 
        return audio;
 }
 
+
 AVSampleFormat
 FFmpegDecoder::audio_sample_format (shared_ptr<FFmpegAudioStream> stream) const
 {
-       return stream->stream (_format_context)->codec->sample_fmt;
+       return static_cast<AVSampleFormat>(stream->stream(_format_context)->codecpar->format);
 }
 
+
 int
 FFmpegDecoder::bytes_per_audio_sample (shared_ptr<FFmpegAudioStream> stream) const
 {
        return av_get_bytes_per_sample (audio_sample_format (stream));
 }
 
+
 void
 FFmpegDecoder::seek (ContentTime time, bool accurate)
 {
@@ -306,7 +366,7 @@ FFmpegDecoder::seek (ContentTime time, bool accurate)
           we don't really know what the seek will give us.
        */
 
-       ContentTime pre_roll = accurate ? ContentTime::from_seconds (2) : ContentTime (0);
+       auto pre_roll = accurate ? ContentTime::from_seconds (2) : ContentTime (0);
        time -= pre_roll;
 
        /* XXX: it seems debatable whether PTS should be used here...
@@ -318,7 +378,8 @@ FFmpegDecoder::seek (ContentTime time, bool accurate)
        if (_video_stream) {
                stream = _video_stream;
        } else {
-               shared_ptr<FFmpegAudioStream> s = dynamic_pointer_cast<FFmpegAudioStream> (_ffmpeg_content->audio->stream ());
+               DCPOMATIC_ASSERT (_ffmpeg_content->audio);
+               auto s = dynamic_pointer_cast<FFmpegAudioStream>(_ffmpeg_content->audio->stream());
                if (s) {
                        stream = s->index (_format_context);
                }
@@ -326,7 +387,7 @@ FFmpegDecoder::seek (ContentTime time, bool accurate)
 
        DCPOMATIC_ASSERT (stream);
 
-       ContentTime u = time - _pts_offset;
+       auto u = time - _pts_offset;
        if (u < ContentTime ()) {
                u = ContentTime ();
        }
@@ -337,12 +398,20 @@ FFmpegDecoder::seek (ContentTime time, bool accurate)
                AVSEEK_FLAG_BACKWARD
                );
 
+       {
+               /* Force re-creation of filter graphs to reset them and hence to make sure
+                  they don't have any pre-seek frames knocking about.
+               */
+               boost::mutex::scoped_lock lm (_filter_graphs_mutex);
+               _filter_graphs.clear ();
+       }
+
        if (video_codec_context ()) {
                avcodec_flush_buffers (video_codec_context());
        }
 
-       BOOST_FOREACH (shared_ptr<FFmpegAudioStream> i, ffmpeg_content()->ffmpeg_audio_streams()) {
-               avcodec_flush_buffers (i->stream(_format_context)->codec);
+       for (auto i: ffmpeg_content()->ffmpeg_audio_streams()) {
+               avcodec_flush_buffers (_codec_context[i->index(_format_context)]);
        }
 
        if (subtitle_codec_context ()) {
@@ -350,215 +419,282 @@ FFmpegDecoder::seek (ContentTime time, bool accurate)
        }
 
        _have_current_subtitle = false;
-}
 
-void
-FFmpegDecoder::decode_audio_packet ()
-{
-       /* Audio packets can contain multiple frames, so we may have to call avcodec_decode_audio4
-          several times.
-       */
+       for (auto& i: _next_time) {
+               i.second = boost::optional<dcpomatic::ContentTime>();
+       }
+}
 
-       AVPacket copy_packet = _packet;
 
+shared_ptr<FFmpegAudioStream>
+FFmpegDecoder::audio_stream_from_index (int index) const
+{
        /* XXX: inefficient */
-       vector<shared_ptr<FFmpegAudioStream> > streams = ffmpeg_content()->ffmpeg_audio_streams ();
-       vector<shared_ptr<FFmpegAudioStream> >::const_iterator stream = streams.begin ();
-       while (stream != streams.end () && !(*stream)->uses_index (_format_context, copy_packet.stream_index)) {
+       auto streams = ffmpeg_content()->ffmpeg_audio_streams();
+       auto stream = streams.begin();
+       while (stream != streams.end() && !(*stream)->uses_index(_format_context, index)) {
                ++stream;
        }
 
        if (stream == streams.end ()) {
-               /* The packet's stream may not be an audio one; just ignore it in this method if so */
-               return;
+               return {};
        }
 
-       while (copy_packet.size > 0) {
-
-               int frame_finished;
-               int decode_result = avcodec_decode_audio4 ((*stream)->stream (_format_context)->codec, _frame, &frame_finished, &copy_packet);
-               if (decode_result < 0) {
-                       /* avcodec_decode_audio4 can sometimes return an error even though it has decoded
-                          some valid data; for example dca_subframe_footer can return AVERROR_INVALIDDATA
-                          if it overreads the auxiliary data.  ffplay carries on if frame_finished is true,
-                          even in the face of such an error, so I think we should too.
+       return *stream;
+}
 
-                          Returning from the method here caused mantis #352.
-                       */
-                       LOG_WARNING ("avcodec_decode_audio4 failed (%1)", decode_result);
 
-                       /* Fudge decode_result so that we come out of the while loop when
-                          we've processed this data.
-                       */
-                       decode_result = copy_packet.size;
+void
+FFmpegDecoder::process_audio_frame (shared_ptr<FFmpegAudioStream> stream)
+{
+       auto frame = audio_frame (stream);
+       auto data = deinterleave_audio (frame);
+
+       ContentTime ct;
+       if (frame->pts == AV_NOPTS_VALUE) {
+               /* In some streams we see not every frame coming through with a timestamp; for those
+                  that have AV_NOPTS_VALUE we need to work out the timestamp ourselves.  This is
+                  particularly noticeable with TrueHD streams (see #1111).
+                  */
+               if (_next_time[stream]) {
+                       ct = *_next_time[stream];
                }
+       } else {
+               ct = ContentTime::from_seconds (
+                       frame->best_effort_timestamp *
+                       av_q2d (stream->stream(_format_context)->time_base))
+                       + _pts_offset;
+       }
 
-               if (frame_finished) {
-                       ContentTime ct = ContentTime::from_seconds (
-                               av_frame_get_best_effort_timestamp (_frame) *
-                               av_q2d ((*stream)->stream (_format_context)->time_base))
-                               + _pts_offset;
+       _next_time[stream] = ct + ContentTime::from_frames(data->frames(), stream->frame_rate());
 
-                       shared_ptr<AudioBuffers> data = deinterleave_audio (*stream);
+       if (ct < ContentTime()) {
+               /* Discard audio data that comes before time 0 */
+               auto const remove = min (int64_t(data->frames()), (-ct).frames_ceil(double(stream->frame_rate())));
+               data->move (data->frames() - remove, remove, 0);
+               data->set_frames (data->frames() - remove);
+               ct += ContentTime::from_frames (remove, stream->frame_rate());
+       }
 
-                       if (ct < ContentTime ()) {
-                               /* Discard audio data that comes before time 0 */
-                               Frame const remove = min (int64_t (data->frames()), (-ct).frames_ceil(double((*stream)->frame_rate ())));
-                               data->move (data->frames() - remove, remove, 0);
-                               data->set_frames (data->frames() - remove);
-                               ct += ContentTime::from_frames (remove, (*stream)->frame_rate ());
-                       }
+       if (ct < ContentTime()) {
+               LOG_WARNING (
+                       "Crazy timestamp %1 for %2 samples in stream %3 (ts=%4 tb=%5, off=%6)",
+                       to_string(ct),
+                       data->frames(),
+                       stream->id(),
+                       frame->best_effort_timestamp,
+                       av_q2d(stream->stream(_format_context)->time_base),
+                       to_string(_pts_offset)
+                       );
+       }
 
-                       if (ct < ContentTime()) {
-                               LOG_WARNING ("Crazy timestamp %1", to_string (ct));
-                       }
+       /* Give this data provided there is some, and its time is sane */
+       if (ct >= ContentTime() && data->frames() > 0) {
+               audio->emit (film(), stream, data, ct);
+       }
+}
 
-                       /* Give this data provided there is some, and its time is sane */
-                       if (ct >= ContentTime() && data->frames() > 0) {
-                               audio->emit (*stream, data, ct);
-                       }
+
+void
+FFmpegDecoder::decode_and_process_audio_packet (AVPacket* packet)
+{
+       auto stream = audio_stream_from_index (packet->stream_index);
+       if (!stream) {
+               return;
+       }
+
+       auto context = _codec_context[stream->index(_format_context)];
+       auto frame = audio_frame (stream);
+
+       int r = avcodec_send_packet (context, packet);
+       if (r < 0) {
+               LOG_WARNING("avcodec_send_packet returned %1 for an audio packet", r);
+       }
+       while (r >= 0) {
+               r = avcodec_receive_frame (context, frame);
+               if (r == AVERROR(EAGAIN)) {
+                       /* More input is required */
+                       return;
                }
 
-               copy_packet.data += decode_result;
-               copy_packet.size -= decode_result;
+               /* We choose to be relaxed here about other errors; it seems that there may be valid
+                * data to decode even if an error occurred.  #352 may be related (though this was
+                * when we were using an old version of the FFmpeg API).
+                */
+               process_audio_frame (stream);
        }
 }
 
+
 bool
-FFmpegDecoder::decode_video_packet ()
+FFmpegDecoder::decode_and_process_video_packet (AVPacket* packet)
 {
        DCPOMATIC_ASSERT (_video_stream);
 
-       int frame_finished;
-       if (avcodec_decode_video2 (video_codec_context(), _frame, &frame_finished, &_packet) < 0 || !frame_finished) {
+       auto context = video_codec_context();
+
+       int r = avcodec_send_packet (context, packet);
+       if (r < 0) {
+               LOG_WARNING("avcodec_send_packet returned %1 for a video packet", r);
+       }
+
+       r = avcodec_receive_frame (context, _video_frame);
+       if (r == AVERROR(EAGAIN) || r == AVERROR_EOF || (r < 0 && !packet)) {
+               /* More input is required, no more frames are coming, or we are flushing and there was
+                * some error which we just want to ignore.
+                */
                return false;
+       } else if (r < 0) {
+               throw DecodeError (N_("avcodec_receive_frame"), N_("FFmpeg::decode_and_process_video_packet"), r);
        }
 
+       process_video_frame ();
+
+       return true;
+}
+
+
+void
+FFmpegDecoder::process_video_frame ()
+{
+       /* We assume we'll only get one frame here, which I think is safe */
+
        boost::mutex::scoped_lock lm (_filter_graphs_mutex);
 
        shared_ptr<VideoFilterGraph> graph;
 
-       list<shared_ptr<VideoFilterGraph> >::iterator i = _filter_graphs.begin();
-       while (i != _filter_graphs.end() && !(*i)->can_process (dcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format)) {
+       auto i = _filter_graphs.begin();
+       while (i != _filter_graphs.end() && !(*i)->can_process(dcp::Size(_video_frame->width, _video_frame->height), (AVPixelFormat) _video_frame->format)) {
                ++i;
        }
 
        if (i == _filter_graphs.end ()) {
-               graph.reset (new VideoFilterGraph (dcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format));
+               dcp::Fraction vfr (lrint(_ffmpeg_content->video_frame_rate().get() * 1000), 1000);
+               graph = make_shared<VideoFilterGraph>(dcp::Size(_video_frame->width, _video_frame->height), (AVPixelFormat) _video_frame->format, vfr);
                graph->setup (_ffmpeg_content->filters ());
                _filter_graphs.push_back (graph);
-               LOG_GENERAL (N_("New graph for %1x%2, pixel format %3"), _frame->width, _frame->height, _frame->format);
+               LOG_GENERAL (N_("New graph for %1x%2, pixel format %3"), _video_frame->width, _video_frame->height, _video_frame->format);
        } else {
                graph = *i;
        }
 
-       list<pair<shared_ptr<Image>, int64_t> > images = graph->process (_frame);
+       auto images = graph->process (_video_frame);
 
-       for (list<pair<shared_ptr<Image>, int64_t> >::iterator i = images.begin(); i != images.end(); ++i) {
+       for (auto const& i: images) {
 
-               shared_ptr<Image> image = i->first;
+               auto image = i.first;
+
+               if (i.second != AV_NOPTS_VALUE) {
+                       double const pts = i.second * av_q2d(_format_context->streams[_video_stream.get()]->time_base) + _pts_offset.seconds();
 
-               if (i->second != AV_NOPTS_VALUE) {
-                       double const pts = i->second * av_q2d (_format_context->streams[_video_stream.get()]->time_base) + _pts_offset.seconds ();
                        video->emit (
-                               shared_ptr<ImageProxy> (new RawImageProxy (image)),
-                               llrint (pts * _ffmpeg_content->active_video_frame_rate ())
+                               film(),
+                               make_shared<RawImageProxy>(image),
+                               llrint(pts * _ffmpeg_content->active_video_frame_rate(film()))
                                );
                } else {
                        LOG_WARNING_NC ("Dropping frame without PTS");
                }
        }
-
-       return true;
 }
 
+
 void
-FFmpegDecoder::decode_subtitle_packet ()
+FFmpegDecoder::decode_and_process_subtitle_packet (AVPacket* packet)
 {
        int got_subtitle;
        AVSubtitle sub;
-       if (avcodec_decode_subtitle2 (subtitle_codec_context(), &sub, &got_subtitle, &_packet) < 0 || !got_subtitle) {
+       if (avcodec_decode_subtitle2 (subtitle_codec_context(), &sub, &got_subtitle, packet) < 0 || !got_subtitle) {
                return;
        }
 
+       auto sub_period = subtitle_period (packet, ffmpeg_content()->subtitle_stream()->stream(_format_context), sub);
+
        /* Stop any current subtitle, either at the time it was supposed to stop, or now if now is sooner */
        if (_have_current_subtitle) {
                if (_current_subtitle_to) {
-                       subtitle->emit_stop (min(*_current_subtitle_to, subtitle_period(sub).from + _pts_offset));
+                       only_text()->emit_stop (min(*_current_subtitle_to, sub_period.from + _pts_offset));
                } else {
-                       subtitle->emit_stop (subtitle_period(sub).from + _pts_offset);
+                       only_text()->emit_stop (sub_period.from + _pts_offset);
                }
                _have_current_subtitle = false;
        }
 
        if (sub.num_rects <= 0) {
                /* Nothing new in this subtitle */
+               avsubtitle_free (&sub);
                return;
        }
 
        /* Subtitle PTS (within the source, not taking into account any of the
           source that we may have chopped off for the DCP).
        */
-       FFmpegSubtitlePeriod sub_period = subtitle_period (sub);
        ContentTime from;
        from = sub_period.from + _pts_offset;
-       _have_current_subtitle = true;
        if (sub_period.to) {
                _current_subtitle_to = *sub_period.to + _pts_offset;
+       } else {
+               _current_subtitle_to = optional<ContentTime>();
+               _have_current_subtitle = true;
        }
 
        for (unsigned int i = 0; i < sub.num_rects; ++i) {
-               AVSubtitleRect const * rect = sub.rects[i];
+               auto const rect = sub.rects[i];
 
                switch (rect->type) {
                case SUBTITLE_NONE:
                        break;
                case SUBTITLE_BITMAP:
-                       decode_bitmap_subtitle (rect, from);
+                       process_bitmap_subtitle (rect, from);
                        break;
                case SUBTITLE_TEXT:
                        cout << "XXX: SUBTITLE_TEXT " << rect->text << "\n";
                        break;
                case SUBTITLE_ASS:
-                       decode_ass_subtitle (rect->ass, from);
+                       process_ass_subtitle (rect->ass, from);
                        break;
                }
        }
 
+       if (_current_subtitle_to) {
+               only_text()->emit_stop (*_current_subtitle_to);
+       }
+
        avsubtitle_free (&sub);
 }
 
+
 void
-FFmpegDecoder::decode_bitmap_subtitle (AVSubtitleRect const * rect, ContentTime from)
+FFmpegDecoder::process_bitmap_subtitle (AVSubtitleRect const * rect, ContentTime from)
 {
-       /* Note RGBA is expressed little-endian, so the first byte in the word is R, second
-          G, third B, fourth A.
+       /* Note BGRA is expressed little-endian, so the first byte in the word is B, second
+          G, third R, fourth A.
        */
-       shared_ptr<Image> image (new Image (AV_PIX_FMT_RGBA, dcp::Size (rect->w, rect->h), true));
+       auto image = make_shared<Image>(AV_PIX_FMT_BGRA, dcp::Size (rect->w, rect->h), Image::Alignment::PADDED);
 
 #ifdef DCPOMATIC_HAVE_AVSUBTITLERECT_PICT
        /* Start of the first line in the subtitle */
-       uint8_t* sub_p = rect->pict.data[0];
-       /* sub_p looks up into a BGRA palette which is here
+       auto sub_p = rect->pict.data[0];
+       /* sub_p looks up into a BGRA palette which is at rect->pict.data[1];
           (i.e. first byte B, second G, third R, fourth A)
        */
-       uint32_t const * palette = (uint32_t *) rect->pict.data[1];
+       auto const palette = rect->pict.data[1];
 #else
        /* Start of the first line in the subtitle */
-       uint8_t* sub_p = rect->data[0];
-       /* sub_p looks up into a BGRA palette which is here
-          (i.e. first byte B, second G, third R, fourth A)
+       auto sub_p = rect->data[0];
+       /* sub_p looks up into a BGRA palette which is at rect->data[1].
+          (first byte B, second G, third R, fourth A)
        */
-       uint32_t const * palette = (uint32_t *) rect->data[1];
+       auto const* palette = rect->data[1];
 #endif
        /* And the stream has a map of those palette colours to colours
           chosen by the user; created a `mapped' palette from those settings.
        */
-       map<RGBA, RGBA> colour_map = ffmpeg_content()->subtitle_stream()->colours ();
+       auto colour_map = ffmpeg_content()->subtitle_stream()->colours();
        vector<RGBA> mapped_palette (rect->nb_colors);
        for (int i = 0; i < rect->nb_colors; ++i) {
-               RGBA c ((palette[i] & 0xff0000) >> 16, (palette[i] & 0xff00) >> 8, palette[i] & 0xff, (palette[i] & 0xff000000) >> 24);
-               map<RGBA, RGBA>::const_iterator j = colour_map.find (c);
+               RGBA c (palette[2], palette[1], palette[0], palette[3]);
+               auto j = colour_map.find (c);
                if (j != colour_map.end ()) {
                        mapped_palette[i] = j->second;
                } else {
@@ -568,56 +704,84 @@ FFmpegDecoder::decode_bitmap_subtitle (AVSubtitleRect const * rect, ContentTime
                        */
                        mapped_palette[i] = c;
                }
+               palette += 4;
        }
 
        /* Start of the output data */
-       uint32_t* out_p = (uint32_t *) image->data()[0];
+       auto out_p = image->data()[0];
 
        for (int y = 0; y < rect->h; ++y) {
-               uint8_t* sub_line_p = sub_p;
-               uint32_t* out_line_p = out_p;
+               auto sub_line_p = sub_p;
+               auto out_line_p = out_p;
                for (int x = 0; x < rect->w; ++x) {
-                       RGBA const p = mapped_palette[*sub_line_p++];
-                       /* XXX: this seems to be wrong to me (isn't the output image RGBA?) but it looks right on screen */
-                       *out_line_p++ = (p.a << 24) | (p.r << 16) | (p.g << 8) | p.b;
+                       auto const p = mapped_palette[*sub_line_p++];
+                       *out_line_p++ = p.b;
+                       *out_line_p++ = p.g;
+                       *out_line_p++ = p.r;
+                       *out_line_p++ = p.a;
                }
 #ifdef DCPOMATIC_HAVE_AVSUBTITLERECT_PICT
                sub_p += rect->pict.linesize[0];
 #else
                sub_p += rect->linesize[0];
 #endif
-               out_p += image->stride()[0] / sizeof (uint32_t);
+               out_p += image->stride()[0];
        }
 
-       int const target_width = subtitle_codec_context()->width;
-       int const target_height = subtitle_codec_context()->height;
+       int target_width = subtitle_codec_context()->width;
+       if (target_width == 0 && video_codec_context()) {
+               /* subtitle_codec_context()->width == 0 has been seen in the wild but I don't
+                  know if it's supposed to mean something from FFmpeg's point of view.
+               */
+               target_width = video_codec_context()->width;
+       }
+       int target_height = subtitle_codec_context()->height;
+       if (target_height == 0 && video_codec_context()) {
+               target_height = video_codec_context()->height;
+       }
+       DCPOMATIC_ASSERT (target_width);
+       DCPOMATIC_ASSERT (target_height);
        dcpomatic::Rect<double> const scaled_rect (
-               static_cast<double> (rect->x) / target_width,
-               static_cast<double> (rect->y) / target_height,
-               static_cast<double> (rect->w) / target_width,
-               static_cast<double> (rect->h) / target_height
+               static_cast<double>(rect->x) / target_width,
+               static_cast<double>(rect->y) / target_height,
+               static_cast<double>(rect->w) / target_width,
+               static_cast<double>(rect->h) / target_height
                );
 
-       subtitle->emit_image_start (from, image, scaled_rect);
+       only_text()->emit_bitmap_start (from, image, scaled_rect);
 }
 
+
 void
-FFmpegDecoder::decode_ass_subtitle (string ass, ContentTime from)
+FFmpegDecoder::process_ass_subtitle (string ass, ContentTime from)
 {
        /* We have no styles and no Format: line, so I'm assuming that FFmpeg
           produces a single format of Dialogue: lines...
        */
 
-       vector<string> bits;
-       split (bits, ass, is_any_of (","));
-       if (bits.size() < 10) {
+       int commas = 0;
+       string text;
+       for (size_t i = 0; i < ass.length(); ++i) {
+               if (commas < 9 && ass[i] == ',') {
+                       ++commas;
+               } else if (commas == 9) {
+                       text += ass[i];
+               }
+       }
+
+       if (text.empty ()) {
                return;
        }
 
        sub::RawSubtitle base;
-       list<sub::RawSubtitle> raw = sub::SSAReader::parse_line (base, bits[9]);
+       auto raw = sub::SSAReader::parse_line (
+               base,
+               text,
+               _ffmpeg_content->video->size().width,
+               _ffmpeg_content->video->size().height
+               );
 
-       BOOST_FOREACH (sub::Subtitle const & i, sub::collect<list<sub::Subtitle> > (raw)) {
-               subtitle->emit_text_start (from, i);
+       for (auto const& i: sub::collect<vector<sub::Subtitle>>(raw)) {
+               only_text()->emit_plain_start (from, i);
        }
 }