Build: Promote libswresample to a required dependency

FFmpeg is an integral component of ZM. Promote the appropriate libraries to required dependencies.
This reduces the possible build configurations greatly and thus maintenance burden.

CMakeLists.txt

@@ -443,6 +443,7 @@ find_package(FFMPEG REQUIRED
     avcodec
     avformat
     avutil
+    swresample
     swscale)
 
 set(CMAKE_REQUIRED_INCLUDES ${FFMPEG_avutil_INCLUDE_DIRS})
@@ -458,16 +459,6 @@ else()
   set(optlibsnotfound "${optlibsnotfound} AVDevice")
 endif()
 
-find_package(FFMPEG COMPONENTS swresample)
-if(FFMPEG_swresample_FOUND)
-  set(HAVE_LIBSWRESAMPLE 1)
-  set(HAVE_LIBSWRESAMPLE_SWRESAMPLE_H 1)
-  list(APPEND ZM_BIN_LIBS "FFMPEG::swresample")
-  set(optlibsfound "${optlibsfound} SWResample")
-else()
-  set(optlibsnotfound "${optlibsnotfound} SWResample")
-endif()
-
 set(PATH_FFMPEG "")
 set(OPT_FFMPEG "no")
 

src/CMakeLists.txt

@@ -80,6 +80,7 @@ target_link_libraries(zm
     FFMPEG::avcodec
     FFMPEG::avformat
     FFMPEG::avutil
+    FFMPEG::swresample
     FFMPEG::swscale
     libbcrypt::bcrypt
     RtspServer::RtspServer

src/zm_ffmpeg.cpp

@@ -635,7 +635,6 @@ void zm_packet_copy_rescale_ts(const AVPacket *ipkt, AVPacket *opkt, const AVRat
   av_packet_rescale_ts(opkt, src_tb, dst_tb);
 }
 
-#if defined(HAVE_LIBSWRESAMPLE)
 int zm_resample_audio(SwrContext *resample_ctx, AVFrame *in_frame, AVFrame *out_frame) {
   if (in_frame) {
     // Resample the in_frame into the audioSampleBuffer until we process the whole
@@ -659,7 +658,6 @@ int zm_resample_audio(SwrContext *resample_ctx, AVFrame *in_frame, AVFrame *out_
 int zm_resample_get_delay(SwrContext *resample_ctx, int time_base) {
   return swr_get_delay(resample_ctx, time_base);
 }
-#endif
 
 int zm_add_samples_to_fifo(AVAudioFifo *fifo, AVFrame *frame) {
   int ret = av_audio_fifo_realloc(fifo, av_audio_fifo_size(fifo) + frame->nb_samples);

src/zm_ffmpeg.h

@@ -24,21 +24,18 @@
 #include "zm_define.h"
 
 extern "C" {
-
-#ifdef HAVE_LIBSWRESAMPLE
-#include "libswresample/swresample.h"
-#endif
+#include <libswresample/swresample.h>
 
 // AVUTIL
-#include "libavutil/avassert.h"
+#include <libavutil/avassert.h>
 #include <libavutil/avutil.h>
 #include <libavutil/base64.h>
 #include <libavutil/mathematics.h>
 #include <libavutil/avstring.h>
-#include "libavutil/audio_fifo.h"
-#include "libavutil/imgutils.h"
+#include <libavutil/audio_fifo.h>
+#include <libavutil/imgutils.h>
 #if HAVE_LIBAVUTIL_HWCONTEXT_H
-  #include "libavutil/hwcontext.h"
+  #include <libavutil/hwcontext.h>
 #endif
 
 /* LIBAVUTIL_VERSION_CHECK checks for the right version of libav and FFmpeg
@@ -411,10 +408,8 @@ int zm_send_frame_receive_packet(AVCodecContext *context, AVFrame *frame, AVPack
 
 void zm_packet_copy_rescale_ts(const AVPacket *ipkt, AVPacket *opkt, const AVRational src_tb, const AVRational dst_tb);
 
-#if defined(HAVE_LIBSWRESAMPLE)
 int zm_resample_audio(SwrContext *resample_ctx, AVFrame *in_frame, AVFrame *out_frame);
 int zm_resample_get_delay(SwrContext *resample_ctx, int time_base);
-#endif
 
 int zm_add_samples_to_fifo(AVAudioFifo *fifo, AVFrame *frame);
 int zm_get_samples_from_fifo(AVAudioFifo *fifo, AVFrame *frame);

src/zm_videostore.cpp

@@ -87,10 +87,8 @@ VideoStore::VideoStore(
   packets_written(0),
   frame_count(0),
   hw_device_ctx(nullptr),
-#if defined(HAVE_LIBSWRESAMPLE)
   resample_ctx(nullptr),
   fifo(nullptr),
-#endif
   converted_in_samples(nullptr),
   filename(filename_in),
   format(format_in),
@@ -722,7 +720,6 @@ VideoStore::~VideoStore() {
 #endif
     }
 
-#if defined(HAVE_LIBSWRESAMPLE)
     if (resample_ctx) {
       if (fifo) {
         av_audio_fifo_free(fifo);
@@ -742,7 +739,6 @@ VideoStore::~VideoStore() {
       av_free(converted_in_samples);
       converted_in_samples = nullptr;
     }
-#endif
   } // end if audio_out_stream
 
   Debug(4, "free context");
@@ -753,10 +749,6 @@ VideoStore::~VideoStore() {
 } // VideoStore::~VideoStore()
 
 bool VideoStore::setup_resampler() {
-#if !defined(HAVE_LIBSWRESAMPLE)
-  Error("Not built with resample library. Cannot do audio conversion to AAC");
-  return false;
-#else
   int ret;
 
 #if LIBAVCODEC_VERSION_CHECK(57, 64, 0, 64, 0)
@@ -925,7 +917,6 @@ bool VideoStore::setup_resampler() {
     Error("Could not allocate FIFO");
     return false;
   }
-#if defined(HAVE_LIBSWRESAMPLE)
   resample_ctx = swr_alloc_set_opts(nullptr,
       audio_out_ctx->channel_layout,
       audio_out_ctx->sample_fmt,
@@ -948,7 +939,6 @@ bool VideoStore::setup_resampler() {
     return false;
   }
   Debug(1,"Success setting up SWRESAMPLE");
-#endif
 
   out_frame->nb_samples = audio_out_ctx->frame_size;
   out_frame->format = audio_out_ctx->sample_fmt;
@@ -984,7 +974,6 @@ bool VideoStore::setup_resampler() {
   }
 
   return true;
-#endif
 }  // end bool VideoStore::setup_resampler()
 
 int VideoStore::writePacket(const std::shared_ptr<ZMPacket> &ipkt) {

src/zm_videostore.h

@@ -9,12 +9,10 @@
 #include <memory>
 
 extern "C"  {
-#ifdef HAVE_LIBSWRESAMPLE
-#include "libswresample/swresample.h"
-#endif
-#include "libavutil/audio_fifo.h"
+#include <libswresample/swresample.h>
+#include <libavutil/audio_fifo.h>
 #if HAVE_LIBAVUTIL_HWCONTEXT_H
-#include "libavutil/hwcontext.h"
+#include <libavutil/hwcontext.h>
 #endif
 }
 
@@ -70,10 +68,8 @@ class VideoStore {
 
     AVBufferRef *hw_device_ctx;
 
-#ifdef HAVE_LIBSWRESAMPLE
     SwrContext *resample_ctx;
     AVAudioFifo *fifo;
-#endif
     uint8_t *converted_in_samples;
 
     const char *filename;

zoneminder-config.cmake

@@ -37,8 +37,6 @@
 #cmakedefine HAVE_LIBAVDEVICE 1
 #cmakedefine HAVE_LIBAVDEVICE_AVDEVICE_H 1
 #cmakedefine HAVE_LIBAVUTIL_HWCONTEXT_H 1
-#cmakedefine HAVE_LIBSWRESAMPLE 1
-#cmakedefine HAVE_LIBSWRESAMPLE_SWRESAMPLE_H 1
 #cmakedefine HAVE_LIBVLC 1
 #cmakedefine HAVE_VLC_VLC_H 1
 #cmakedefine HAVE_LIBVNC 1