src/zm_ffmpeg_input.cpp
Rama master · réplica de lectura del repositorio original.
#include "zm_ffmpeg_input.h"
#include "zm_ffmpeg.h"
#include "zm_logger.h"
FFmpeg_Input::FFmpeg_Input() :
streams(nullptr),
video_stream_id(-1),
audio_stream_id(-1),
input_format_context(nullptr),
last_seek_request(-1),
hw_device_ctx(nullptr)
{
FFMPEGInit();
}
FFmpeg_Input::~FFmpeg_Input() {
if (input_format_context) {
Close();
}
} // end ~FFmpeg_Input()
/* Takes streams provided from elsewhere. They might not come from the same source
* but we will treat them as if they are. */
int FFmpeg_Input::Open(
const AVStream * video_in_stream,
const AVCodecContext * video_in_ctx,
const AVStream * audio_in_stream,
const AVCodecContext * audio_in_ctx
) {
int max_stream_index = video_stream_id = video_in_stream->index;
if (audio_in_stream) {
max_stream_index = video_in_stream->index > audio_in_stream->index ? video_in_stream->index : audio_in_stream->index;
audio_stream_id = audio_in_stream->index;
}
streams = new stream[max_stream_index+1];
return 1;
}
int FFmpeg_Input::Open(const char *filepath) {
int error;
/** Open the input file to read from it. */
error = avformat_open_input(&input_format_context, filepath, nullptr, nullptr);
if ( error < 0 ) {
if (std::string(filepath).find("incomplete") != std::string::npos) {
Warning("Could not open input file '%s' (error '%s')",
filepath, av_make_error_string(error).c_str());
} else {
Error("Could not open input file '%s' (error '%s')",
filepath, av_make_error_string(error).c_str());
}
input_format_context = nullptr;
return error;
}
/** Get information on the input file (number of streams etc.). */
if ( (error = avformat_find_stream_info(input_format_context, nullptr)) < 0 ) {
Error(
"Could not open find stream info (error '%s')",
av_make_error_string(error).c_str()
);
avformat_close_input(&input_format_context);
return error;
}
streams = new stream[input_format_context->nb_streams];
Debug(2, "Have %d streams", input_format_context->nb_streams);
for (unsigned int i = 0; i < input_format_context->nb_streams; i += 1) {
//av_seek_frame(input_format_context, i, 0, AVSEEK_FLAG_FRAME);
if (is_video_stream(input_format_context->streams[i])) {
zm_dump_stream_format(input_format_context, i, 0, 0);
if (video_stream_id == -1) {
video_stream_id = i;
// if we break, then we won't find the audio stream
} else {
Warning("Have another video stream.");
}
} else if (is_audio_stream(input_format_context->streams[i])) {
if (audio_stream_id == -1) {
Debug(2, "Audio stream is %d", i);
audio_stream_id = i;
} else {
Warning("Have another audio stream.");
}
} else {
Warning("Unknown stream type");
}
streams[i].frame_count = 0;
streams[i].context = nullptr;
std::list<const CodecData *>codec_data = get_decoder_data(input_format_context->streams[i]->codecpar->codec_id, "auto");
for (auto it = codec_data.begin(); it != codec_data.end(); it ++) {
const CodecData *chosen_codec_data = *it;
Debug(1, "Found codec %s", chosen_codec_data->codec_name);
streams[i].codec = avcodec_find_decoder_by_name(chosen_codec_data->codec_name);
streams[i].context = avcodec_alloc_context3(streams[i].codec);
avcodec_parameters_to_context(streams[i].context, input_format_context->streams[i]->codecpar);
if (setup_hwaccel(streams[i].context,
chosen_codec_data, hw_device_ctx, "",
input_format_context->streams[i]->codecpar->width,
input_format_context->streams[i]->codecpar->height
)) {
Warning("Failed to setup hw_accel");
continue;
}
zm_dump_codec(streams[i].context);
error = avcodec_open2(streams[i].context, streams[i].codec, nullptr);
if (error < 0) {
Error("Could not open input codec (error '%s')",
av_make_error_string(error).c_str());
avcodec_free_context(&(streams[i].context));
streams[i].context = nullptr;
continue;
}
break;
} // end foreach codec_data
if (!streams[i].context) {
Debug(1, "Failed with known codecs, trying harder");
streams[i].context = open_fallback_decoder(
input_format_context->streams[i]->codecpar, &streams[i].codec);
}
if (!streams[i].context) {
//avformat_close_input(&input_format_context);
//input_format_context = nullptr;
continue;
}
zm_dump_codec(streams[i].context);
if (0 and !(streams[i].context->time_base.num && streams[i].context->time_base.den)) {
Debug(1, "Setting to default time base");
streams[i].context->time_base.num = 1;
streams[i].context->time_base.den = 90000;
}
} // end foreach stream
if (video_stream_id == -1)
Debug(1, "Unable to locate video stream in %s", filepath);
if (audio_stream_id == -1)
Debug(3, "Unable to locate audio stream in %s", filepath);
return 1;
} // end int FFmpeg_Input::Open( const char * filepath )
int FFmpeg_Input::Close( ) {
if (streams && input_format_context) {
for (unsigned int i = 0; i < input_format_context->nb_streams; i += 1) {
//avcodec_close(streams[i].context);
avcodec_free_context(&streams[i].context);
streams[i].context = nullptr;
}
delete[] streams;
streams = nullptr;
}
if (input_format_context) {
avformat_close_input(&input_format_context);
input_format_context = nullptr;
}
return 1;
} // end int FFmpeg_Input::Close()
AVFrame *FFmpeg_Input::get_frame(int stream_id) {
if (!streams[stream_id].context) {
Error("No context for stream %d", stream_id);
return nullptr;
}
bool frameComplete = false;
av_packet_ptr packet{av_packet_alloc()};
if (!packet) {
Error("Unable to allocate packet.");
return nullptr;
}
AVCodecContext *context = streams[stream_id].context;
while (!frameComplete) {
frame = av_frame_ptr{av_frame_alloc()};
if (!frame) {
Error("Unable to allocate frame.");
return nullptr;
}
// Since technically sending a packet can result in multiple frames (or buffered_frames) try receive_frame first.
int ret = avcodec_receive_frame(context, frame.get());
Debug(1, "Ret from receive_frame ret: %d %s", ret, av_make_error_string(ret).c_str());
if (ret == AVERROR(EAGAIN)) {
// Perfectly normal
} else if (ret < 0) {
Error("Ret from receive_frame ret: %d %s", ret, av_make_error_string(ret).c_str());
return nullptr;
} else {
frameComplete = true;
if (is_video_stream(input_format_context->streams[packet->stream_index])) {
zm_dump_video_frame(frame.get(), "resulting video frame");
} else {
zm_dump_frame(frame.get(), "resulting frame");
}
break;
}
ret = av_read_frame(input_format_context, packet.get());
if (ret < 0) {
if (
// Check if EOF.
(ret == AVERROR_EOF || (input_format_context->pb && input_format_context->pb->eof_reached)) ||
// Check for Connection failure.
(ret == -110)
) {
Info("av_read_frame returned %s.", av_make_error_string(ret).c_str());
return nullptr;
}
Error("Unable to read packet from stream %d: error %d \"%s\".",
packet->stream_index, ret, av_make_error_string(ret).c_str());
return nullptr;
}
ZM_DUMP_STREAM_PACKET(input_format_context->streams[packet->stream_index], packet, "Received packet");
av_packet_guard pkt_guard{packet};
if ((stream_id >= 0) && (packet->stream_index != stream_id)) {
Debug(4, "Packet is not for our stream (%d)", packet->stream_index );
continue;
}
ret = avcodec_send_packet(context, packet.get());
if (ret == AVERROR(EAGAIN)) {
Debug(2, "Unable to send packet %d %s", ret, av_make_error_string(ret).c_str());
continue;
}
if (ret < 0) {
Error("Unable to send packet %d %s", ret, av_make_error_string(ret).c_str());
return nullptr;
}
} // end while !frameComplete
return frame.get();
} // end AVFrame *FFmpeg_Input::get_frame
/* at is FPSeconds */
AVFrame *FFmpeg_Input::get_frame(int stream_id, double at) {
Debug(1, "Getting frame from stream %d at %f", stream_id, at);
int64_t seek_target = (int64_t)(at * AV_TIME_BASE);
Debug(1, "Getting frame from stream %d at seektarget: %" PRId64, stream_id, seek_target);
seek_target = av_rescale_q(seek_target, AV_TIME_BASE_Q, input_format_context->streams[stream_id]->time_base);
Debug(1, "Getting frame from stream %d at %" PRId64, stream_id, seek_target);
int ret;
if (!frame) {
// Don't have a frame yet, so get a keyframe before the timestamp
ret = av_seek_frame(input_format_context, stream_id, seek_target, AVSEEK_FLAG_FRAME);
if (ret < 0) {
Error("Unable to seek in stream");
return nullptr;
}
// Have to grab a frame to update our current frame to know where we are
get_frame(stream_id);
if (!frame) {
Warning("Unable to get frame.");
return nullptr;
}
// If the initial seek landed past the target (on a future keyframe),
// re-seek backward to get the keyframe before the target instead.
if (frame->pts > seek_target) {
Debug(1, "Initial seek overshot: frame pts %" PRId64 " > seek_target %" PRId64 ", seeking backward",
frame->pts, seek_target);
ret = av_seek_frame(input_format_context, stream_id, seek_target,
AVSEEK_FLAG_BACKWARD);
if (ret >= 0) {
get_frame(stream_id);
}
}
} // end if ! frame
if (
(last_seek_request >= 0)
&&
(last_seek_request > seek_target)
&&
(frame->pts > seek_target)
) {
zm_dump_frame(frame, "frame->pts > seek_target, seek backwards");
// our frame must be beyond our seek target. so go backwards to before it
if (( ret = av_seek_frame(input_format_context, stream_id, seek_target,
AVSEEK_FLAG_BACKWARD | AVSEEK_FLAG_FRAME
) ) < 0) {
Error("Unable to seek in stream %d", ret);
return nullptr;
}
// Have to grab a frame to update our current frame to know where we are
get_frame(stream_id);
if ( is_video_stream(input_format_context->streams[stream_id]) ) {
zm_dump_video_frame(frame, "frame->pts > seek_target, got");
} else {
zm_dump_frame(frame, "frame->pts > seek_target, got");
}
} else if ( last_seek_request == seek_target ) {
// paused case, sending keepalives
return frame.get();
} // end if frame->pts > seek_target
last_seek_request = seek_target;
// If more than 5 seconds behind seek target, use av_seek_frame to jump
// ahead instead of decoding packets sequentially (which is very slow for
// large gaps). 5 seconds is well beyond a typical GOP, making seek
// worthwhile even after decoding forward from the nearest keyframe.
int64_t seek_threshold = av_rescale_q(5 * AV_TIME_BASE, AV_TIME_BASE_Q,
input_format_context->streams[stream_id]->time_base);
if (frame->pts + seek_threshold < seek_target)
{
Debug(1, "Jumping ahead to %" PRId64, seek_target);
if (( ret = av_seek_frame(input_format_context, stream_id, seek_target, AVSEEK_FLAG_FRAME) ) < 0) {
Error("Unable to seek in stream %d", ret);
return nullptr;
}
// Have to grab a frame to update our current frame to know where we are
get_frame(stream_id);
zm_dump_frame(frame, "got");
if (frame->pts > seek_target) {
if (( ret = av_seek_frame(input_format_context, stream_id, seek_target,
AVSEEK_FLAG_FRAME|AVSEEK_FLAG_BACKWARD
) ) < 0) {
Error("Unable to seek in stream %d", ret);
return nullptr;
}
get_frame(stream_id);
zm_dump_frame(frame, "Had to seek backwards");
}
}
// Seeking seems to typically seek to a keyframe, so then we have to decode until we get the frame we want.
if (frame->pts <= seek_target) {
Debug(1, "Frame pts %" PRId64 " + duration %" PRId64 "= %" PRId64 " <=? %" PRId64,
frame->pts,
#if LIBAVCODEC_VERSION_CHECK(60, 3, 0, 3, 0)
frame->duration, frame->pts + frame->duration,
#else
frame->pkt_duration, frame->pts + frame->pkt_duration,
#endif
seek_target);
while (frame && (frame->pts +
#if LIBAVCODEC_VERSION_CHECK(60, 3, 0, 3, 0)
frame->duration
#else
frame->pkt_duration
#endif
< seek_target)) {
if (is_video_stream(input_format_context->streams[stream_id])) {
zm_dump_video_frame(frame, "pts <= seek_target");
} else {
zm_dump_frame(frame, "pts <= seek_target");
}
if (!get_frame(stream_id)) {
Warning("Got no frame. returning nothing");
return nullptr;
}
}
return frame.get();
}
return get_frame(stream_id);
}