diff options
Diffstat (limited to 'src/lib/ffmpeg_decoder.cc')
| -rw-r--r-- | src/lib/ffmpeg_decoder.cc | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc index 767299ea6..ca35c6e81 100644 --- a/src/lib/ffmpeg_decoder.cc +++ b/src/lib/ffmpeg_decoder.cc @@ -27,6 +27,7 @@ #include <iomanip> #include <iostream> #include <stdint.h> +#include <boost/lexical_cast.hpp> extern "C" { #include <tiffio.h> #include <libavcodec/avcodec.h> @@ -56,15 +57,20 @@ FFmpegDecoder::FFmpegDecoder (boost::shared_ptr<const FilmState> s, boost::share , _format_context (0) , _video_stream (-1) , _audio_stream (-1) + , _subtitle_stream (-1) , _frame (0) , _video_codec_context (0) , _video_codec (0) , _audio_codec_context (0) , _audio_codec (0) + , _subtitle_codec_context (0) + , _subtitle_codec (0) + , _have_subtitle (false) { setup_general (); setup_video (); setup_audio (); + setup_subtitle (); } FFmpegDecoder::~FFmpegDecoder () @@ -76,6 +82,14 @@ FFmpegDecoder::~FFmpegDecoder () if (_video_codec_context) { avcodec_close (_video_codec_context); } + + if (_have_subtitle) { + avsubtitle_free (&_subtitle); + } + + if (_subtitle_codec_context) { + avcodec_close (_subtitle_codec_context); + } av_free (_frame); avformat_close_input (&_format_context); @@ -101,6 +115,8 @@ FFmpegDecoder::setup_general () _video_stream = i; } else if (_format_context->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO) { _audio_stream = i; + } else if (_format_context->streams[i]->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) { + _subtitle_stream = i; } } @@ -156,6 +172,26 @@ FFmpegDecoder::setup_audio () } } +void +FFmpegDecoder::setup_subtitle () +{ + if (_subtitle_stream < 0) { + return; + } + + _subtitle_codec_context = _format_context->streams[_subtitle_stream]->codec; + _subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id); + + if (_subtitle_codec == 0) { + throw DecodeError ("could not find subtitle decoder"); + } + + if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) { + throw DecodeError ("could not open subtitle decoder"); + } +} + + bool FFmpegDecoder::do_pass () { @@ -210,6 +246,18 @@ FFmpegDecoder::do_pass () assert (_audio_codec_context->channels == _fs->audio_channels); process_audio (_frame->data[0], data_size); } + + } else if (_subtitle_stream >= 0 && _packet.stream_index == _subtitle_stream && _fs->with_subtitles) { + + if (_have_subtitle) { + avsubtitle_free (&_subtitle); + _have_subtitle = false; + } + + int got_subtitle; + if (avcodec_decode_subtitle2 (_subtitle_codec_context, &_subtitle, &got_subtitle, &_packet) && got_subtitle) { + _have_subtitle = true; + } } av_free_packet (&_packet); @@ -310,3 +358,107 @@ FFmpegDecoder::sample_aspect_ratio_denominator () const return _video_codec_context->sample_aspect_ratio.den; } +void +FFmpegDecoder::overlay (shared_ptr<Image> image) const +{ + if (!_have_subtitle) { + return; + } + + /* subtitle PTS in seconds */ + float const packet_time = (_subtitle.pts / AV_TIME_BASE) + float (_subtitle.pts % AV_TIME_BASE) / 1e6; + /* hence start time for this sub */ + float const from = packet_time + (float (_subtitle.start_display_time) / 1e3); + float const to = packet_time + (float (_subtitle.end_display_time) / 1e3); + + float const video_frame_time = float (last_video_frame ()) / rint (_fs->frames_per_second); + + if (from > video_frame_time || video_frame_time < to) { + return; + } + + for (unsigned int i = 0; i < _subtitle.num_rects; ++i) { + AVSubtitleRect* rect = _subtitle.rects[i]; + if (rect->type != SUBTITLE_BITMAP) { + throw DecodeError ("non-bitmap subtitles not yet supported"); + } + + /* XXX: all this assumes YUV420 in image */ + + assert (rect->pict.data[0]); + + /* Start of the first line in the target image */ + uint8_t* frame_y_p = image->data()[0] + rect->y * image->line_size()[0]; + uint8_t* frame_u_p = image->data()[1] + (rect->y / 2) * image->line_size()[1]; + uint8_t* frame_v_p = image->data()[2] + (rect->y / 2) * image->line_size()[2]; + + int const hlim = min (rect->y + rect->h, image->size().height) - rect->y; + + /* Start of the first line in the subtitle */ + uint8_t* sub_p = rect->pict.data[0]; + /* sub_p looks up into a RGB palette which is here */ + uint32_t const * palette = (uint32_t *) rect->pict.data[1]; + + for (int sub_y = 0; sub_y < hlim; ++sub_y) { + /* Pointers to the start of this line */ + uint8_t* sub_line_p = sub_p; + uint8_t* frame_line_y_p = frame_y_p + rect->x; + uint8_t* frame_line_u_p = frame_u_p + (rect->x / 2); + uint8_t* frame_line_v_p = frame_v_p + (rect->x / 2); + + /* U and V are subsampled */ + uint8_t next_u = 0; + uint8_t next_v = 0; + int subsample_step = 0; + + for (int sub_x = 0; sub_x < rect->w; ++sub_x) { + + /* RGB value for this subtitle pixel */ + uint32_t const val = palette[*sub_line_p++]; + + int const red = (val & 0xff); + int const green = (val & 0xff00) >> 8; + int const blue = (val & 0xff0000) >> 16; + float const alpha = ((val & 0xff000000) >> 24) / 255.0; + + /* Alpha-blend Y */ + int const cy = *frame_line_y_p; + *frame_line_y_p++ = int (cy * (1 - alpha)) + int (RGB_TO_Y_CCIR (red, green, blue) * alpha); + + /* Store up U and V */ + next_u |= ((RGB_TO_U_CCIR (red, green, blue, 0) & 0xf0) >> 4) << (4 * subsample_step); + next_v |= ((RGB_TO_V_CCIR (red, green, blue, 0) & 0xf0) >> 4) << (4 * subsample_step); + + if (subsample_step == 1 && (sub_y % 2) == 0) { + int const cu = *frame_line_u_p; + int const cv = *frame_line_v_p; + + *frame_line_u_p++ = + int (((cu & 0x0f) * (1 - alpha) + (next_u & 0x0f) * alpha)) | + int (((cu & 0xf0) * (1 - alpha) + (next_u & 0xf0) * alpha)); + + *frame_line_v_p++ = + int (((cv & 0x0f) * (1 - alpha) + (next_v & 0x0f) * alpha)) | + int (((cv & 0xf0) * (1 - alpha) + (next_v & 0xf0) * alpha)); + + next_u = next_v = 0; + } + + subsample_step = (subsample_step + 1) % 2; + } + + sub_p += rect->pict.linesize[0]; + frame_y_p += image->line_size()[0]; + if ((sub_y % 2) == 0) { + frame_u_p += image->line_size()[1]; + frame_v_p += image->line_size()[2]; + } + } + } +} + +bool +FFmpegDecoder::has_subtitles () const +{ + return (_subtitle_stream != -1); +} |